A diagnostic catalog of the causes & cures of of dimming light fixtures or flickering lights & power losses.  

How to diagnose the causes of flickering or dimming lights at or in buildings.

This article gives simple diagnostic steps that a homeowner can do to determine the type of electrical system problem that is causing flickering or dimming lights or intermittent loss of electrical power. We list the common causes of these problems and suggest what to do about them.

Watch out:  flickering or dimming lights often indicates a dangerous condition. Switch off the bad acting appliance or circuit and ask for help from a licensed electrician.

Dimming or Flickering Lights Indicate Electrical Hazards in Buildings: What to Do

Watch out: flickering or dimming lights at a building may be more than an inconvenience.

While some causes of flickering lights may be normal and harmless, such as flickering in certain types of light bulbs, many others indicate a dangerous condition, risking fire, shock, injury or worse.

The safest approach is to turn off electrical circuits or components that are causing flickering or dimming or acting strangely in any way.

If you cannot safely access your electrical panel to turn off dangerous circuits or components, leave the building and call your local emergency services.

At FLOOD & DISASTER BUILDING DAMAGE REPAIR PROCEDURES we list emergency numbers for various countries from Australia (000) to the U.K. (112). In Canada or the U.S. call 911. In Mexico call 066.

[Click to enlarge any image]

Photo: a fluorescent light fixture may be the only electrical device that is flickering, for any of several reasons we will explain below. Other causes of flickering lights are very dangerous.

How to Diagnose Dimming or Flickering Lights at Buildings

In diagnosing the cause of flickering or dimming lights at a building the following diagnostic questions can help narrow down the cause of the trouble.

1. Is the dimming light or power loss problem happening in just your building 
   
   or do neighbors see the same problem at exactly the same time?
   
   If your neighbors are seeing flickering or dimming lights too, chances are the problem is in the electrical supply network or possibly at local electrical wiring in your neighborhood or its power transformer. If your neighborhood frequently loses electrical power
   
   see BACKUP ELECTRICAL GENERATORS
2. Is the dimming problem or power loss showing up in the whole building or just parts of it?
   
   If all lights in the building dim, flicker, or if all power is lost, then the problem is probably in the electrical panel or at the service entry cabling to your building.
   
   The electrician will look for a problem in the electrical panel, at the main breaker, at the service entry wiring connections or at the SEC wiring itself, including the two hot wires and the service neutral wire. But see the exception in step 4 below.
   
   If the dimming, flickering, or lost power occurs in multiple circuits in the building the problem could still be in the electrical panel itself, or in the service entry wiring to the building.
   
   See examples of electric meter failures
   
   at ELECTRIC METERS & METER BASES
   
   Also see ELECTRICAL SERVICE ENTRY WIRING - home
3. Is the dimming or flickering light problem or power loss associated with circuits in just half of the electrical panel? 
   
   Depending on electrical panel layout, damage to one panel bus can cause failures or odd behaviour on electrical circuits connected to that panel bus.
   
   See the power loss traced to electric meter failures
   
   at ELECTRIC METER ARC BURN POWER LOSS
   
   Also see ELECTRICAL SERVICE ENTRY WIRING - home
4. Is the dimming light problem or power loss associated with the operation of a single, specific appliance or motor? 
   
   This is an exception to the case described in step 2 in that all lights may dim when there is a developing failure in a single major appliance such as an air conditioner compressor motor.
   
   Such motors can draw very high amps (current) for just a brief moment when the motor is starting.
   
   If the current surge is very brief, no circuit breaker may trip but the load may be sufficient to dim all of the incandescent lights that are on or all of fixtures in just part of the building, depending on how the appliance circuit is wired in the electrical panel. (Fluorescent lights probably won't dim).
   
   If the problem never occurs when the circuit to that appliance has been turned off you've probably found the trouble.
   
   If the problem is traced to a specific appliance but is intermittent, other variations in conditions such as temperature, humidity, vibration, or moving around of a loose wire may explain that inconsistency.
   
   See also ELECTRIC MOTOR DIAGNOSTIC GUIDE - home
5. Is the dimming or flickering light or power loss showing up on just a single circuit? 
   
   In this case we suspect a faulty circuit breaker or bad connection in the circuit.
   
   Some circuit breaker brands are particularly prone to failure such as FPE Stab-Lok and Zinsco-Sylvania. In this case the problem may ultimately show up on additional circuits in the same building, depending on building age and circuit usage levels and other conditions.
   
   See ELECTRICITY TURN ON AFTER BREAKER TRIP
   
   See CIRCUIT BREAKER FAILURE RATES
   
   Also see these examples of problematic electrical panels
• FEDERAL PACIFIC FPE HAZARDS
• MURRAY CIRCUIT BREAKER HAZARDS
• MURRAY SIEMENS Recall
• PUSHMATIC - BULLDOG PANELS
• SIEMENS MURRAY Recall
• SPLIT BUS ELECTRICAL PANEL HAZARDS
• SQUARE-D AFCI RECALL 2004
• SQUARE-D COUNTERFEIT BREAKER RECALL
• ZINSCO SYLVANIA ELECTRICAL PANELS
6. Is the dimming or flickering light or power loss showing up just at some fixtures or appliances? 
   
   A likely cause of this problem is a failing appliance or motor that is drawing abnormally high current as we cited in step 4.
   
   But sometimes the problem may occur only at lights or appliances plugged in electrically "downstream" from a specific electrical circuit, or at lights operated by a specific switch. In this case we suspect the trouble is not the appliance itself but in connectors within the receptacle or switch or immediately "upstream" (electrically) from it.
   
   Some receptacle and switch types such as older push-in back-wired devices are more likely to have loose or failing electrical connectors with age and usage.
   
   Try plugging in the light fixture or appliance at a different location on a different electrical circuit in the home. If the bad behavior continues then the trouble is in the light or appliance itself.
7. Is the flickering light showing up at just one light fixture?
   
   Look for loose wiring or an overheating fixture.

8. Is the flickering light found in a fluorescent fixture?
   
   If so, while checking for a loose wire or poor fluorescent bulb connection is important, the most common causes of flickering fluorescent light fixtures are

• A bad fluorescent light bulb
  
  take a bulb from a fixture working properly and test it in the flickering fixture; also look for black or other discoloration in the flickering bulb. Replace it.
• A bad starter in the fixture
• A bad ballast in the fixture

In the photo above I am showing the original data tag for this Fox Co. fluorescent fixture installed in the bathroom of a Minnesota home built in 1961.

To stop the flickering light in this luminaire fixture I needed to replace the ballast.

Details of repairing dead, humming, dim, or flickering fluorescent lights are

at FLUORESCENT LIGHT REPAIRS.

Watch out: for flickering light safety hazards and take the immediate safety measures listed here.

18 Causes of Dimming or Flickering Lights or Electrical Power Loss at Buildings

Start by turning off any electrical appliance or circuit that is misbehaving. If you are not trained and familiar with safe electrical practices and repairs, keep your fingers off of the wiring - you could be shocked or killed or could cause a fire. Call for help from a licensed electrician.

Check your local telephone listings for licensed electricians or

see DIRECTORY OF ELECTRICIANS

1. Aluminum electrical wiring: 
   
   if your building's branch circuit wiring (such as lights or electrical receptacles) was installed in the 1970's, solid-conductor aluminum wiring may have been used. With age, use, and mechanical disturbance, the connectors in an aluminum-wired circuit become unsafe, ultimately overheating.
   
   These connections can become hot enough to start a building fire without ever tripping a circuit breaker or blowing a fuse. We have had reports from homeowners of both conventional buildings and mobile homes or doublewides who described flickering lights that indicated trouble traced to aluminum electrical wiring.
   
   Watch out: for this fire hazard. If your home's branch circuits (receptacles and lighting) are wired with aluminum wire, flickering, dimming lights or even sparking may show up on just one circuit but the hazard is building-wide and significant. Turn off the misbehaving circuit and have the electrical system inspected and repaired by an electrician familiar with the hazards of and proper repairs for aluminum wiring.
   
   See ALUMINUM WIRING HAZARDS & REPAIRS - home - aluminum wire connections failing may cause flickering lights or loss of power
   
   Also see MOBILE HOME ELECTRICAL SYSTEMS
2. Appliance or motor drawing high current:
   
   Any appliance that draws high current (amperage). Sometimes this is normal such as a brief high current draw when some large electric motors start, such as an air conditioning or heat pump compressor.
   
   An air conditioner or heat pump compressor motor may draw considerably higher amps at start-up than it does once the motor has begun to run.
   
   That's why installers should use a slow-blow fuse or slow-trip circuit breaker and it's why air conditioning circuit over-current protection ("breaker size" or "fuse size") is typically permitted to be one size larger (more amps) than the rating of the wire supplying the circuit.
   
   For example, an air conditioner may run on a #10 copper wire 30 Amp circuit but may be fused with a 35A or 40A circuit breaker to avoid nuisance tripping when the A/C unit is starting normally.
   
   But dimming lights can also mean that a motor is drawing high current because it is having difficulty starting.
   
   That in turn can be due to a motor that is seizing or due to a failing start-capacitor. Some of these conditions are unsafe. If the motor or appliance trips a circuit breaker, leave that appliance turned off until it can be repaired or replaced.
   
   See HARD STARTING COMPRESSOR MOTORS
   
   Also TIGHT or SEIZED AC COMPRESSORS
   
   See HARD STARTING ELECTRIC MOTOR CAUSES
   
   Also see ELECTRIC MOTOR DIAGNOSTIC GUIDE which describes steps & tests for both offline and online electric motor circuit analysis (MCA) test procedures for hard starting or non-starting A/C electric motors
   
   Technical note: see DATA TAGS on AIR CONDITIONERS for definitions of LRA (lock rotor amps) and RLA (running load amps).
   
   There you'll see that the data tag on an air conditioner or heat pump specifies two different amps or current ratings:
   
   the maximum circuit ampacity (for example 15A) that must be supported by the actual wiring - this is the current drawn when the motor is running
   
   and
   
   the maximum overcurrent protection (for example 20A) that is permitted on the circuit. Typically the data tag will also specify that the installer should use a time delay fuse or HVACR type circuit breaker.
   
   Watch out: many air conditioning and heat pump units are wired with multi-strand aluminum electrical wire - a perfectly legal choice.
   
   But because there is a higher risk of corrosion, resistance, and overheating at the connections of aluminum wiring, if your A/C or heat pump unit is causing severe light dimming or light flickering it makes sense to ask your electrician to check the condition of the wiring and its connections - that will reduce the risk of a total failure or worse, a fire.
   
   Watch out: When you can trace flickering or dimming lights to a single appliance, unplug it and stop using it until it can be inspected and repaired.
   
   If the appliance is a unit such as central air or a heat pump, switch it off at the electrical panel.
3. Corrosion from unanticipated sources:
   
   homes where Chinese drywall was installed were reported to have strange electrical problems including flickering lights.
   
   Off gassing from Chinese drywall was found to cause corrosion of copper components throughout some of these buildings, including HVAC components, cooling coils, and copper electrical wiring or connectors.
   
   See BACKWIRED RECEPTACLE FAILURE REPORT for an example of corroded electrical connections probably contributing to loss of electrical power
   
   See CHINESE DRYWALL HAZARDS
4. Electrical circuit breaker defects:
   
   some brands or models of circuit breaker are known to have significantly higher failure rates than that equipment in general. Examples include Federal Pacific Electric Stab-Lok circuit breakers and Zinsco circuit breakers.
   
   Watch out: fire or shock hazard: When you trace flickering or dimming lights to a specific electrical circuit, turn that circuit off at the electrical panel until your electrician can inspect and repair the problem.
   
   See CIRCUIT BREAKER FAILURE RATES - a bad circuit breaker or electrical panel connection can cause flickering lights or loss of power. This article lists common or well-known problem circuit breaker or electrical panel brands or models.
   
   Since a failing circuit breaker or device sometimes (not always) suffers internal arcing that produces a buzzing sound, that clue may also be diagnostic. Switch such circuits off.
   
   See NOISES, ELECTRICAL SYSTEM
5. Electrical circuit wiring defects:
   
   specific electrical circuits may be dimming or intermittently losing power if the wiring has become damaged or its electrical connectors are loose.
   
   Typically this problem shows up first on just one electrical circuit, or on all of the lights or receptacles ("wall plugs or outlets") downstream from a specific point (where a problem has occurred). A double-wide homeowner reported loss of lights on just one side of a room.
   
   After confirming that no GFCI device had tripped causing a power loss and no circuit breaker had tripped, the owner needed to ask for help from an electrician to find the open wire. For examples
   
   See BACK-WIRED ELECTRICAL DEVICES - home - poor connections lead to flickering lights and loss of electrical power
   
   See BACKWIRED RECEPTACLE FAILURE REPORT - corrosion and poor electrical connections in a beachfront home lead to loss of electrical power
   
   See KNOB & TUBE WIRING
6. Electric fan or LED bulb induced "light flicker":
   
   when certain fluorescent or LED lights or in particular when an overhead fan is in use, depending on factors such as the location of light sources and fan in the room, fan speed, fan blade size and who knows what else can cause an apparent flickering of light where the fan is located. (Kent 2020)
   
   This is not an electrical problem but one of light and shadow.
   
   However depending on the flickering light speed, this condition can be uncomfortable for some people and may be hazardous for some who have particular medical concerns such as light-sensitive epilepsy.
   
   Video games and TVs can also produce flickering light that can be a problem for the same occupants.
7. Electric motor defects:
   
   motors drawing high or excessive current can cause dimming or flickering lights
   
   CAPACITORS for HARD STARTING MOTORS - a hard-starting motor drawing high current may cause flickering lights
8. Electrical panel defects:
   
   as we cite for circuit breakers, some electrical panel brands experience failures far more often than is generally the case among their peers, often because of innate design or manufacturing problems.
   
   Some of these electrical panel defects show up as flickering lights, dimming lights, or loss of power on one or more electrical circuits.
   
   See FEDERAL PACIFIC FPE HAZARDS
   
   Also see ZINSCO SYLVANIA ELECTRICAL PANELS for examples.
   
   A complete list is at ELECTRICAL DISTRIBUTION PANELS in buildings, safety for electrical inspectors, electrical panel, fusing, wiring defects, defective products.
   
   Also see CORROSION in ELECTRICAL PANELS - corrosion on electrical wire or components can cause flickering lights or loss of power
9. Electrical service supply defects & voltage fluctuations:
   
   depending on where you live, weather, loads on the community electrical system, age and condition of the electrical grid and power generation can cause dimming or flickering lights.
   
   If this is the source of trouble at your building, your neighbors will see the same conditions as you.
   
   Sometimes we monitor voltage being delivered to a building to check the range of voltage variation but of course if your electric company's supply is varying significantly, you and your neighbors will all see dimming lights or total loss of power.
   
   Problems at a local power transformer can cause the lights of your home and those of your neighbors to flicker or dim or go out entirely.
   
   Some light flickering, outages that last 60 seconds or less, are referred to in the power industry as "momentary outages" while voltage drops - not a total loss of power but a reduction in the voltage being delivered to a building are referred to as "voltage drops".
   
   According to Florida Power and Light (FPL), these may be caused by lightning strikes, damaged electrical equipment, animals interfering with electrical equipment (including a mouse in your electrical panel), and in coastal areas, salt spray that affects power company equipment or wiring.
   
   A "voltage sag" - momentary drop in the voltage level below its nominal 120VAC - may also occur, which explains why some lights may dim.
   
   These conditions can re-set or stop operation of computers and other electrical devices unless you have a battery-backup uninterruptible power supply (UPS) installed. - FPL "Power Flickers - Reducing Power Flickers", Florida Power and Light, retrieved 9 Nov 2015, original source: https://www.fpl.com/reliability/power-disturbances/flickers.html
   
   According to Canada's CCOHC, "Usually voltage fluctuations are small and do not have adverse effects on electrical equipment.
   
   However, in offices, for example, voltage fluctuations of just a few tenths of one percent can produce very annoying flickers in the lighting, especially if they are regular and repetitive in the 5-15 Hz range." - CCOHS (2015 cited below)
   
   See ELECTRICAL SERVICE ENTRY DAMAGE - damaged electrical feeders or service entry can cause flickering lights or loss of electrical power
   
   See VOLTS MEASUREMENT METHODS
   
   Also see DOUBLE FAULT, LOSS OF ELECTRICITY where we describe faulty wiring at a single building that led to flickering lights and ultimately, loss of power.
10. Electrical service connection failure:
    
    a loose connection at the building's electrical service entry cable or damage to the service entry wiring itself can cause flickering lights or loss of power.
    
    I've seen this problem occur in one side of a 240V electrical panel, causing ultimate loss of power to half of the electrical circuits in the home.
    
    See SERVICE ENTRY WIRING & AMPACITY
    
    Also see ELECTRICAL SERVICE ENTRY WIRING - how is electrical power brought to the building: inspection, troubleshooting, defects
11. Electrical neutral connection failure:
    
    if the electrical system's neutral connection or neutral wiring is faulty, such as a loose connection in the electrical panel, lights in the building may sporadically flicker or dim or power may even be lost intermittently.
    
    I've seen this problem occur when a metal fence post was driven through an underground feeder. A case history that was finally resolved by finding a problem with the electrical utility company's neutral is given
    
    at FLICKERING LIGHTS, LOST NEUTRAL
    
    See also LOST NEUTRAL SHOCKS HOMEOWNER
12. Fluorescent light ballast & other light bulb problems: 
    
    fluorescent lights that use a ballast to produce the voltage needed to drive the light fixture may suffer from a ballast failure.
    
    The ballast, a "black box" found inside of fluorescent light fixtures may cause humming or buzzing sounds heard near the light fixture as well as flickering lights.
    
    This problem occurs where older magnetic type ballasts are installed. Newer electronic ballasts don't hum or buzz.
    
    See FLUORESCENT LIGHT REPAIRS where we describe repairing flicking fluorescent light fixtures.
    
    Also see LIGHTING, INTERIOR GUIDE where buzzing ballasts are discussed.
    
    Separately we discuss eliminating the ballast entirely by switching to an LED bulb - an option available for some fluorescent fixtures.
    
    See LED BULB REPLACES FLUORESCENT
    
13. Lightning strikes 
    
    can damage both area electrical wiring or the supply grid as well as damaging components at an individual building.
    
    A frequent sufferer of lighting strikes are well pumps and well pump wiring at properties where a submersible well pump is in a steel-casing well in an area subject to frequent lightning storms.
    
    In this case the problem is usually confined to the well circuit, but I have participated in investigation of more extreme damage to all of a building's wiring and even plumbing systems due to lightning strikes.
    
    See LIGHTNING PROTECTION SYSTEMS
14. Light fixture or light bulb or bulb socket / wiring defects:
    
    flickering lights that occur only at a single light fixture may be caused by a failing or defective light bulb, particularly if the bulb is a traditional incandescent type.
    
    As the filament in an incandescent light bulb begins to fail it may become loose and intermittently "open" electrically causing the light to flicker.
    Tapping gently on such a bulb may cause it to go out completely. Changing the bulb should fix the trouble.
    
    If the individual light fixture continues to flicker after a new bulb has been installed, check that the bulb itself is ok by trying it in a different light fixture.
    
    If the light bulb is not defective then I suspect a bad bulb socket in the light fixture or a loose wire connection in the light fixture's connection to its power circuit. Turn the fixture off until it can be repaired or replaced.
    
    A loose, corroded, or cracked, broken bulb connector or incandescent or LED bulb socket can also cause flickering lights. [Thanks to reader Jan for reminding us of this cause, 2020/10/29 ]
15. Loose electrical connections in an electrical circuit:
    
    loose splices or connections anywhere in an electrical circuit can cause flickering lights. Usually this defect shows up just on the circuit that contains the faulty connection.
    
    I've seen this problem at an electrical receptacle that received very frequent use: devices were constantly plugged-in then removed.
    
    The wiggling and jiggling of the device loosened contacts intended to be made between the receptacle and the wall plug.
    
    Other receptacles or switches may be wiggled around in their electrical box (if poorly-secured) causing loose, failing electrical connections.
    
    See ELECTRICAL SPLICES, HOW TO MAKE - a bad splice, wire connector or loose screw or wire can cause flickering lights or loss of power
    
    In some cases, such as back-wired push-in type electrical receptacles, the wiring connector itself (a small spring) is inherently weaker than screw-type connectors. On older homes these connections can fail, occasionally leading to a fire.
    
    See BACK-WIRED ELECTRICAL DEVICES
16. Low or varying voltage
    
    from the electrical service utility or due to defects in the service drop or service entry wiring.
    
    VOLTS MEASUREMENT METHODS - voltage variation may cause flickering lights
17. Outdoor electrical wiring defects:
    
    aside from the service entry cable problems I've cited, other outdoor wiring defects can cause flickering lights on those circuits. Examples include lighting fixtures or receptacles that have become wet.
18. Something else is wrong:
    
    the list above is certainly not exhaustive and there may be other causes of flickering or dimming lights that we should add here. Please use the page bottom CONTACT link to let us know what we've missed or add a comment in the Comments section below.

Watch out: flickering or dimming lights may, depending on the cause, indicate a dangerous condition. Arcing or overheating at electrical circuits can ultimately lead not only to power loss but to a building fire.

That's why we recommend turning off misbehaving electrical equipment while you wait for the electrician.

What Level of Flickering Light Can People See?

Canada's CCOHS has written some of the most easily understood description of who sees flickering lights, what people can see or sense, and what health effects may occur when exposed to flickering light. Excerpts are below:

People can see lights flashing on and off up to about 50 flashes per second (50 Hz) - they are most sensitive to time-varying illumination in the 10-25 Hz range. The actual critical flicker frequency increases as the light intensity increases up to a maximum value, after which it starts to decrease.

When a light is flickering at a frequency greater than 50 or so Hertz, most people can no longer distinguish between the individual flickers.

At this frequency - the critical flicker frequency or flicker fusion threshold - the flashes appear to fuse into a steady, continuous source of light. This happens because the response to the light stimulus lasts longer than the flash itself.

Most people cannot notice the flicker in fluorescent lights that have a flicker rate of 120 cycles per second (or 120 Hz).

The light flicker may be detected by its stroboscopic effect. When objects move or rotate rapidly, they may be lit at or about the same position during each cycle or rotation.

This makes objects look as if they are moving more slowly than their actual speeds - they may even appear stationary if the object is moving at the same rate as the flicker frequency (or a multiple of it).

This fact is the principle behind a strobe light but it is not the desired effect in general lighting. In fact, it could be a safety hazard if someone mistakenly thought that some equipment was stationary or was moving slowly. - CCOHS, "Lighting Ergonomics - Light Flicker", Canadian Centre for Occupational Health and Safety, CCOHS, retrieved 2015/11/09, original source: http://www.ccohs.ca/oshanswers/ergonomics/lighting_flicker.html

Also, from a different source, we see that flickering light can be a source of eye strain and headaches even if it is not related to electrical malfunctions that we listed earlier in this article:

... the use of high frequency electronic ballasts (20,000 Hz or higher) in fluorescent lights resulted in more than a 50% drop in complaints of eye strain and headaches.

There tended to be fewer complaints of headaches among workers on higher floors compared to those closer to ground level; that is, workers exposed to more natural light experienced fewer health effects. - Wilkins, A. J., I. Nimmo-Smith, A. I. Slater, and L. Bedocs. "Fluorescent lighting, headaches and eyestrain." Lighting Research and Technology 21, no. 1 (1989): 11-18.

Flickering lights traced to bad utility company neutral wire

This topic has moved to FLICKERING LIGHTS, LOST NEUTRAL

Flickering Light Research & References

• Bahobail, Mohammed Ali. SICK BUILDING SYNDROMES AND THEIR EFFECTS ON HOMES WITHIN RIYADH CITY [PDF] (2013) Journal Architecture & Planning 25, no. 2 (2013): 69-78.
  Excerpt:
  Light Glare, flicker, lack of contrast, inadequate illumination or unsuitable lighting might cause tiredness, dry eyes and headaches.
  
  People commonly feel unwell after spending time in buildings that are illuminated by fluorescent lights due to their flicker. The flickering light is very harsh and tends to give healthy people headaches and other symptoms.
  
  Also, it is found that conventional white fluorescent lighting is likely to cause eyestrain and headaches.
  
  People can see flicker lights, flashing on and off up to about 50 flashes per second (50 Hz).
  
  However, flickers above 50 Hz cannot be noticed, but this does not mean that it cannot affect people.
• Boyce, Peter R. "The impact of light in buildings on human health." Indoor and Built environment 19, no. 1 (2010): 8-20. Dahlquist, Neil R., James F. Mellinger, and Donald W. Klass. "Hazard of video games in patients with light-sensitive epilepsy." JAMA 249, no. 6 (1983): 776-777.
• Dahlquist, Neil R., James F. Mellinger, and Donald W. Klass. "Hazard of video games in patients with light-sensitive epilepsy." JAMA 249, no. 6 (1983): 776-777.
• Friedman, Deborah I., and Timothy De Ver Dye. "Migraine and the environment." Headache: The Journal of Head and Face Pain 49, no. 6 (2009): 941-952.
  Excerpt:
  Less often, flickering lights (strobe light, variable light …
• Girgis, Adly, John W. Stephens, and Elham B. Makram. "Measurement and prediction of voltage flicker magnitude and frequency." Power Delivery, IEEE Transactions on 10, no. 3 (1995): 1600-1605.
• Jansz, Janis. "Theories and knowledge about sick building syndrome." In Sick building syndrome, pp. 25-58. Springer, Berlin, Heidelberg, 2011.
  Excerpt:
  Lighting problems, eg flicker caused by magnetic ballasts and computer glare, which … and/or fatigue after return to the building Diagnosed infection Discomfort and/or health complaints …
• Kent, Michael G., Toby Cheung, Jiayu Li, and Stefano Schiavon. "Experimental evaluation of visual flicker caused by ceiling fans." Building and Environment 182 (2020): 107060.
• Koeppen, P. (n.d.). Electrical Fast Transients (EFT)/Burst ESD Details. Electrical fast transients (eft)/burst ESD details. Retrieved September 6, 2022, from http://www.esdunlimited.com/eft.html
• Kuller, Rikard, and Thorbjorn Laike. "The impact of flicker from fluorescent lighting on well-being, performance and physiological arousal." Ergonomics 41, no. 4 (1998): 433-447.
• New York State Central Hudson Gas and Electric Company, G&E/1-2/85 consumer safety pamphlet
• Owen, Edward. "Power disturbance and quality: Light flicker voltage requirements." Industry Applications Magazine, IEEE 2, no. 1 (1996): 20-27.
• Pitrak, Laura, BROWNOUTS vs BLACKOUTS - WHAT'S THE DIFFERENCE? [PDF] (2022) Transient Specialists, 7704 S. Grant St., Burr Ridge IL 60527 USA, Tel: 630-887-0329 Email: info@transientspecialists.com Web: transientspecialists.com - retrieved 2022/12/15, original source: https://transientspecialists.com/blogs/blog/brownout-vs-blackout
  Excerpt:
  A power brownout is similar to a blackout, but it refers to a partial loss of power, rather than a complete loss of power.
  
  When a blackout occurs, all appliances and electronics in your home will stop working; in contrast, a brownout reduces voltage by 10% to 25%. A blackout is also unintentional, where a brownout is done on purpose by a utility company. 
• Romero‐Gómez, Manuel, Juan Córdoba, Rodrigo Jover, Juan A. del Olmo, Marta Ramírez, Ramón Rey, Enrique de Madaria et al. "Value of the critical flicker frequency in patients with minimal hepatic encephalopathy." Hepatology 45, no. 4 (2007): 879-885
• Sankaran, C. Power quality. CRC press, 2001.
• Sun, J., D. Czarkowski, and Z. Zabar. "Voltage flicker mitigation using PWM-based distribution STATCOM." In Power Engineering Society Summer Meeting, 2002 IEEE, vol. 1, pp. 616-621. IEEE, 2002.
• Transient Specialists, ELECTRICAL TRANSIENTS - SOURCES, WAVEFORMS & MITIGATION TIPS [PDF] (2022), Transient Specialists, 7704 S. Grant St., Burr Ridge IL 60527 USA, Tel: 630-887-0329 Email: info@transientspecialists.com Web: transientspecialists.com - retrieved 2022/12/15, original source: https://transientspecialists.com/blogs/blog/electrical-transients
  
  Transient Specialists is a small company specializing in EMC test equipment rentals. They are very knowledgeable on the operation of the equipment and the issues that can slow your learning curve when you are renting this equipment for the first time. They have also expanded suppliers as well as markets, to include automotive, military, and product safety.
  
  Excerpts:
  What are Electrical Transients?
  
  Electrical transients are fast risetime, short duration energy pulses that commonly have voltage and current components often transmitted down data or power lines. Common causes of power line transients are when an AC/DC connection is made or broken, equipment powered down, or circuit breakers switched.(Koppen 2022)
  
  Electrical transients cover a wide range of interference and have the potential to impact the operation of electrical systems and equipment. These events can be caused by power grid switching, sudden disconnection or connection, lightning, as well as generated within or by associated electrical equipment.
• Veitch, Jennifer A., and Shelley L. McColl. "Modulation of fluorescent light: Flicker rate and light source effects on visual performance and visual comfort." Lighting Research and technology 27, no. 4 (1995): 243-256.
• Wilkins, Arnold, Jennifer Veitch, and Brad Lehman. "LED lighting flicker and potential health concerns: IEEE standard PAR1789 update." In Energy Conversion Congress and Exposition (ECCE), 2010 IEEE, pp. 171-178. IEEE, 2010.
• Wilkins, A. J., I. Nimmo-Smith, A. I. Slater, and L. Bedocs. "Fluorescent lighting, headaches and eyestrain." Lighting Research and Technology 21, no. 1 (1989): 11-18.
  Abstract:
  The weekly incidence of headaches among office workers was compared when the offices were lit by fluorescent lighting where the fluorescent tubes were operated by
  
  (a) a conventional switch-start circuit with choke ballast providing illumination that pulsated with a modulation depth of 43-49% and a principal frequency component at 100 Hz;
  
  (b) an electronic start circuit with choke ballast giving illumination with similar characteristics;
  
  (c) an electronic ballast driving the lamps at about 32 kHz and reducing the 100 Hz modulation to less than 7%.
  
  In a double-blind cross-over design, the average incidence of headaches and eyestrain was more than halved under high-frequency lighting. The incidence was unaffected by the speed with which the tubes ignited.
  
  Headaches tended to decrease with the height of the office above the ground and thus with increasing natural light. Office occupants chose to switch on the high-frequency lighting for 30% longer on average.
• Winterbottom, Mark, and Arnold Wilkins. "Lighting and discomfort in the classroom." Journal of Environmental Psychology 29, no. 1 (2009): 63-75.
• Zweers, T., L. Preller, B. Brunekreef, and J. S. M. Boleij. "Health and indoor climate complaints of 7043 office workers in 61 buildings in the Netherlands." Indoor Air 2, no. 3 (1992): 127-136.

   

   

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2023-02-05 by Dogs_rule - flickering and dying light cause and repair

I have a 1970s two pin, double fluorescent light in my main bath. The light flickered and died when one tube burned out black at one end. I replaced both tubes and the same tube turned black at one end immediately. So i figured it might be the ballast. When turned on, the light was barely discernable - almost non existent but enough to find my toothbrush.

I've been leaving it for over a year as I will upgrade the lighting when I redo the entire bathroom and a new ballast is almost as expensive here as a newer led light. My question is, after not working for over a year all of a sudden both tubes in the light started to work last night! And again this am.

The one tube with the black end now has black at both ends though. FYI we had some record cold with a wind chill for the last two days. -45 The attic is over the bathroom on the north east corner of the house. There is some ice damning on that corner of the roof as I had new leaf guards installed in the Fall.

I am not going to be turning the light on as I'm quite stumped as to why it would be working all of a sudden after a year. Would like some insight into how this is happening?

When it gets warmer I'll go up in the attic to check the venting and wiring before putting any new parts or a new light in. Thanks much in advance. Puzzled im Canada .

On 2023-02-05 by InspectApedia Publisher - flickering and dying light suddenly worked again

@Dogs_rule,

That sounds as if there could simply be a loose or corroded electrical connection.

On 2023-02-03 by Kate.darling55@gmail.com - lost power after turning on electric heat

I heard a thump and the power went out briefly. None of the fuses turned off. I had just turned out the electric heat to a room I don't usually heat. There was no smell of smoke. I do have mice. How immanently serious is this problem?

On 2023-02-03 by InspectApedia Publisher - heard a thump and the power went out briefly

@Kate darling55,

If you have power everywhere in your home it's possible that the "THUMP" that you heard was outside at a power company's line transformer. ON occasion a power company transformer or its fuse blows, power blinks off, and (luckily for us) there is enough redundancy in the system that power returns to your home via an alternative route.

On 2023-01-03 by Karin Bridges - washing machine causes house lights to flicker

I built a house in 2020. The electrical is having issues. The builder's electrician is stumped, as is the one I hired independently.

The washer is on a separate breaker, yet when it is in its agitation cycle, the lights in the house flicker with the beat. Also, it takes twice as long to cook things like casseroles that I have made or bought from places that come with standard cooking times.

We have had the entire control panel in the oven replaced, and the element is fine. I have also had the connections in the box checked.

Please tell me what else it could be. The electrical panel is an Eaton 200 Amp, and the house is less than 1800 sf. I am at my wit's end trying to solve this and am not sure if the house is safe.

On 2023-01-03 by InspectApedia Publisher - the lights in the house flicker with the beat of the washer agitation cycle

@Karin Bridges,

I appreciate the interesting question but have to duck slightly with the apology that I doubt that we, peering at your home's electrical system through the eye of a needle formed by a brief text, can but guess - your onsite people have to be smarter than we are.

If you're certain that the flickering ONLY occurs when the washer is running, that suggests either a problem with that appliance and / or its circuit, or an electrical problem stimulated by vibration caused by the washer's agitation. Those are clues worth proceeding.

So investigate closely the circuit and connections, starting at the electrical panel. (Something as simple as a corroded or overheated connection or even an aluminum service entry cable that isn't actually very tightly-pinned under the connector-lug-screw can cause flickering lights and other anomalous behaviour in the electrical system).

A connector might look tight and work find when it's not being jiggled around. A closer look is in order.

How electrical connections are made and what devices are used are also critical. Insufficient tightening, back-wiring, using push-in connectors instead of screws, etc. all can cause trouble.

About your oven's cook time, it should be simple to measure the oven temperature and compare it with the setting on the controls. If the actual temperature is close to the control-set-temperature, then the long cook time isn't likely to be related to the electrical system itself. Keep in mind that measured oven temperature is never highly accurate, so just getting in the ballpark of the dial setting is probably all one can expect.

For example "In a nutshell, it’s impossible to control your oven temperature, so you should stop worrying about it altogether—or so writes Slate writer Brian Palmer. While you think might 350 degrees on the dial means 350 in the oven, no residential oven maintains a 350-degree temperature for the duration of a bake session.

Rather, it usually ranges between 330 and 370 degrees and, as Palmer notes, that’s if it’s a well-calibrated oven, which few are. What about oven thermometers, you ask? “A waste of time,” writes Palmer.

The variability in temperature throughout the oven chamber makes oven thermometers unreliable at best." - https://www.thekitchn.com/why-you-should-stop-worrying-about-your-oven-temperature-175602

So instead, compare cooking properties of your oven with other owners of the same model and with others of different models and features.

Kenneth · Oct 18, 2022 Asked why does half of power go off when I turn off the water heater?

Why would half my power go out when i shut the breaker to my water heater off

On 2022-12-16 by InspectApedia (Editor) - Why would half my power go out when i shut the breaker to my water heater off ?

Watch out: when power is lost in one side of a 220V electrical panel, because of how they are wired, a 220V electric water heater might return current from the live panel side back to the "dead" side of an electrical panel, sending current through the electric water heater's heating element.

As it will be a useful diagnostic for readers on this page, we are re-posting the following discussion with readers Kenneth and Juliet that appeared originally at

https://inspectapedia.com/Manufactured_Homes/Mobile-Home-Electrical-System-FAQs.php

Watch out: I suspect the panel is damaged or mis-wired.

Power to breakers on one side of the panel is perhaps being fed through the water heater breaker instead of from the incoming power source on that side.

A bad crossover connector could also be involved but I don't think that alone would explain the situation that you describe.

Any of those is unsafe.

You should get help from a licensed electrician right away.

Let me know

- what the electrician finds

- the brand and age of the electrical panel

- if there is any aluminum wiring

- the building age & location

Please also post a photo of the panel showing the breakers

2022/12/13 Juliet said:

@Kenneth, if you have lost voltage on one incoming line of the 220v in the panel, when the water heater breaker is on it can cause voltage to travel from the one leg of 220v in the panel that has voltage on it thru the water heater element & back to the panel thru the water heater breaker, back feeding 110v to the other leg of the panel buss bar thus putting 110v on the other circuits.

Turn the water heater breaker off & then check to see if you have 220v across the two incoming lines & main breaker.

I think you've lost one leg of the 220v on a main breaker or the incoming line from the meter box.

InspectApedia (Editor) (mod) · 2022/12/13 - said:

@Juliet,

Thank you so much for posting that electrical power loss diagnostic suggestion

"220V Electric water heater can back-power electrical current to one side of an electrical panel"

it's not one that I had come across, and it's very helpful.

On 2022-11-13 by Rob - laser printer causes flickering lights on start up and when printing

Hello - I recently purchased a new laser printer and it cause some light fixture flickering on start up and when printing. Laser printers are known to draw a lot of power on start up and during other activities. The circuit in question is 15A and has a few standard outlets and a few lights on it but the circuit breaker is not tripping.

I can't easily move the printer as it is connected via a USB cable. Do you have any suggestions to solve this problem? Thanks, Rob

On 2022-11-13 by InspectApedia (Editor)

@Rob,

Thank you for an interesting question. It might be diagnostic to try plugging the printer in at another electrical receptacle on the same circuit.

If the lights don't flicker when the printer is used plugged in elsewhere it's possible that the problem is a poor connection or damage at the electrical receptacle where it was plugged in before.

Watch out: If the printer is shaking as it prints it's possible that its vibration is moving its power cord or a table on which other electrical devices are plugged in - shaking might reveal loose wiring in the electrical receptavle.

On 2022-11-10 by Joseph cross - lost power in half of trailer home

So I have a 1979 mobile home 2 bedrooms 1 bath that has lost power to the front half which is the dining room, kitchen, and living room. I see this is a common occurrence for most part but its also effected the stove and water heater. Stove has power but oven Don t get hot. Also our water heater completely quit Don t work at all.

What could be my problem? I haven't seen any post with both half trailer missing power and major appliances not working. Any help is greatly appreciated.

I have already had an electrician come look and he said I was fine yet 20 mins after he left the lights in dining room and kitchen flickered almost turning off so I turned most breakers off duty to being worried my home may burn down.

Please someone help if you can. Thank you & have a good day

On 2022-11-10 by InspectApedia (Editor) - half trailer missing power and major appliances not working

@Joseph cross,

Often when large areas of a mobile home have lost power and particularly when more than one individual electrical circuit is involved, I suspect that the problem starts right in the electrical panel.

For example (this may not be your case) it's possible for all of the circuits on one side of an electrical panel to lose power if one of the two main entry cables has been damaged or is poorly-connected. That problem occurs more-often when the entering service entry wires are aluminum.

Losing power in half the panel can explain why your electric stove might seem to work but not get hot: burners have only half the power intended.

You need to find another electrician, one who is experienced and who knows to check the entering service wire connections in the panel.

You might mention that the service entry wire in the panel (or in the electric meter) might LOOK OK in the panel but may in fact be arc-burned or poorly connected.

The electrician should inspect, clean, tighten those connections and if that makes no difference, may have to inspect similar connections in the electric meter base.

These diagnostic Q&A may help

MOBILE HOME ELECTRICAL - FLICKERING LIGHTS

Keep us posted: what you find will definitely help other readers.

On 2022-10-21 by Jay - all of the lights flicker when small appliances are on and some go dim or go off

When the heater or hair dryer or microwave is on lights dim or flicker throughout the house ....in some areas they vey dim or go off completely.

On 2022-10-21 by InspectApedia (Editor) - heater or hair dryer or microwave cause lights to dim or flicker throughout the house

@Jay,

That sounds like

- an overloaded circuit

- a poor or loose electrical connection

- aluminum electrical wire, if not properly repaired, a fire hazard

Or, of course, something else we've not named

On 2022-09-25 by Lee - why do some electrical circuits sometimes lose power, breakers not tripped?

I have some circuits in my house that lose power intermittently. No breakers tripped. If I turn a 220V appliance on, everything comes back on. Any thoughts what might be happening?
Thanks,
Lee

On 2022-09-25 by InspectApedia (Editor)

@Lee,

I suspect a bad or unsafe connection at a breaker in the electrical panel - so your electrician might start there.

What is the brand of the electrical panel in your home?

Where is the home - country and city?

How old are the home and the panel?

Is there any aluminum wiring in the home?

I would leave the offending circuits turned OFF at the panel until your electrician has examined the panel and wiring.

Let me know what your electrician finds - that may help other readers.

Other causes of flickering lights are given above on this page: do take a look.

 

On 2022-08-08 by jay stevans - steps in diagnosing flilckering blinking lights

I just went through your page on Flickering Lights & Electrical Power Loss, an excellent doc, very nice.

I have been having an intermittent, very intermittent, blinking lights problem for a long time, a couple years as memory serves. Diagnosing it is difficult because it is so intermittent. I have tried to find a pattern, anything I can track down and troubleshoot - no luck.

As background, I am an electrical engineer with 40 years of troubleshooting experience in broadcast radio and tv stations including control room design and construction right down to the very last wire. Even mobile trucks. All that to say, I have a lot of diagnostic and troubleshooting experience.

I am pretty sure, though none of us in the house are really certain, it mostly happens in the kitchen. And most evident in the 5-lamp chandelier in the kitchen/dining area. It may be happening in other rooms though it is far less common there. Then again, we spend so much less time in those rooms so maybe we're missing it.

Anyways, and to the point of my question, I would like to be able to monitor the voltage in a few places as a diagnostic step. Are you aware of a monitoring device that I could connect to various outlets (and use an adapter to clip onto lines where there are no outlets) and whose data I could easily see or even download?

My goal is to determine if these dimming glitches are local to one

I'd be grateful for the assistance.

Jay

On 2022-08-08 by InspectApedia-911 (mod) - voltage monitoring device

@jstevans,

Short answer: no, not that I've seen for casual purchase, installation and use.

Yes, there are industrial process systems and devices that can monitor multiple data points.

Our mentor/associate Dr. Jess Aronstein has demonstrated methods of monitoring multiple points on an electrical circuit, though in that case it was for investigating overheating at connections.

It was a labor-intensive and sensor-intensive approach that involved an electrical engineering's expert selection of sensors, installing them, and connecting them to a computer that in turn had supporting software.

There are of course current monitoring and measuring devices on the market, even simple DMMs and VOMs, but not intended for monitoring multiple points.

** What do you think of starting at the electrical panel: monitor individual circuits starting with the one you suspect.

** Take a look at Eaton's "Power Xpert Multi-Point Meter" and let me know if you think that might be useful.

** What do you think also, about the probability that as little as a single mis-behaving device can create a load that shows up back in the panel to cause flickering lights on one or more circuits?

On 2022-08-09 by Jay

@InspectApedia-911, I have considered the "single mis-behaving device" possibility.

I was hoping I could monitor the voltage in enough places to a) confirm that the voltage is actually dropping and b) perhaps localize it physically or to a specific circuit.

I am pretty sure the effect is primarily in the kitchen. The lighting fixture over the kitchen table is where we see this the most often and the most dramatically. This fixture has 5 dimmable LEDs and is controlled by an LED compatible dimmer. This is actually the second LED compatible dimmer, I was suspicious of the first one. One time the effect was so severe the LEDs in the fixture were strobing. OK for a disco, very wrong for our kitchen.

My next step is to replace the LEDs with incandescents or halogens in an effort to determine if the LEDs/dimmer combination is the cause.

Thanks for your assistance. I'll keep digging through and will try to remember to report back.

Thank you again,

Jay

On 2022-08-09 by InspectApedia-911 (mod)

@jay,

You may have already tried this but a simple diagnostic that is usually where I started to turn off individual devices or lights or circuits one by one to see if that lets us quickly hone it on the cause of the odd electrical behavior.

I'm surprised that voltage drop might be the problem here I and suspect as more likely a bad connection or a failing individual electrical device on the circuit.

It's really easy to monitor the voltage level with a DMM or VOM.

We do see much greater service voltage variation in some locations, such as Central mexico, then others such as Canada or much of the US.

On 2022-08-11 by Jay

@InspectApedia-911, Those are excellent suggestions if the problem occurs often enough. Mine is an "every few days for a few seconds that may repeat momentarily or not for days" situation. That's the devil's own problem to troubleshoot. Thus my hope for long-term monitoring.

BTW, I agree it might be a loose connection and once thought I'd found it so I tightened everything - twice to be sure. Nope, came back a few days later.

Thanks again,

Jay

On 2022-08-11 by InspectApedia-911 (mod)

@Jay

And no fluorescents, no ballasts, no timers, etc, right?

Does the flicker occur when there is a load surge such as a refrigerator or freezer or A/C unit turning on?

On 2022-08-13 by Jay

@InspectApedia-911, I opened the box with the dimmer in it and checked every single connection, I wiggled and pushed and twisted - not a single blink.

Then I saw a little switch or adjustment level on the dimmer I didn't remember having seen when I installed it. So, off to the Internet to find the installation guide. It was a little tiny adjustment lever to set the low-brightness adjustment.

But while I was looking at the installation instructions I saw mention of a "list of compatible LEDs for this dimmer." Back to the Internet where I found the list, which had a handy search tool into which I entered the model of the lamps I have had installed for a couple years - the dimmer manufacturer rates them as only 3 stars out of 4 on the blinking scale.

Whoa, I'd never heard of needing to match LEDs to the dimmer. I did some more research, found a 4-star non-blinker and am awaiting delivery. Maybe, maybe it has always been a mismatch.

TBD.

Jay

On 2022-08-13 by InspectApedia-911 (mod) - list of compatible LEDs for this dimmer

@Jay,

Thanks so much for that update that's interesting and helpful.

I didn't think to suggest that to you but in fact I have, earlier in the life of LEDs, run into cases in which some of the early models were not dimmable.

(As was the case, of course, with fluorescent lights.)

Certainly the least expensive would be to try and existing incandescent bulb in those fixtures to see what happens with your dimmer switch.

Halogens are a bit more efficient but I would prefer to end with a dimmable LED both for Energy savings and in another sense simply because the bulbs run cooler which tends to make less trouble for the fixture in which the bulb is mounted.

A clue is that you will see some LED products mentioned on the packaging that they went can work with dimmers. That's an indirect warning that there are some others that don't work with dimmers and of course there's some variation and how the dimmer switches work themselves.

On 2022-07-06 by Texas Homeowner - flickering lights, aluminum wire, possible improper and unsafe "repair"

Hi all, thanks for the informative website.

I have pigtailed two circuits in my 70s-era home with Alumiconn connectors, however both of the circuits have an issue with light flicker when using another device on the circuit. For example, the floor lamp exhibits a solid on/off when turning on a fan on the same circuit.

This issue presents itself on the closest outlet to the breaker. Any idea on troubleshooting? I had an electrician look and he said it could either be a loose neutral connection, possibly in a j-box between the outlet receptacle and breaker.

I'm a bit concerned that this problem is caused by the Alumiconn installation as only these two circuits are showing this issue. I used the proper stripping length and torque screwdriver.

On 2022-07-07 by InspectApedia-911 (mod)

@Texas Homeowner,

Watch out: I'm concerned as well about the possibility of an electrical fire. I don't know whether the problem is in the connectors that you installed or whether the problem is that you've done an incomplete repair on aluminum wiring circuit. Every single connector in the whole installation needs to be addressed.

You will see it on the page above a very thorough list of causes of flickering lights on circuits. And while you might want to look through that I think we first need to address the question of whether you're aluminum wiring has been properly repaired.

I commend you for using a torque measuring screwdriver I thought I was the only person who owned one. Most electricians have never even seen one much less carried one in their toolbox. But still I don't think that that connector was intended to be used by a homeowner.

The first place to start is to examine the connectors that have been installed because of the possibility that a space limitation or jamming them back into electrical box may have actually caused a connection to be less tight than you thought.

Second just to review your entire electrical wiring system to make sure that the repair is complete and correct by ( as I am obligated to say ) a trained installer.

On 2022-06-25 by Carrie white - hair straightener trips circuit breaker

I was vacuuming n my daughter was in the bathroom straightening her hair the breaker kept flipping off.i turned everything off fans n air-conditioners eventually all the power stayed off in our bathroom and bedroom n part of our laundry room

changed the outlet in the bathroom since it's the ones with the buttons and seems to control other power in other rooms didn't help tested the breaker by switching to another part of the house (dishwasher) it still powered it on any idea what it could be

On 2022-06-04 by Thom - fluorescent bulbs won't light reliably

Looked through your resources. Very helpful and explanatory. My pair of fluorescent bulbs won't light reliably when powered on (maybe 10% of the time) unless I take off the cover and tap on one specific spot on only one of the bulbs – nowhere else. That will make it turn on nearly every time and both bulbs will ignite.

If I turn off the power and then it back on, the bulbs will not turn on unless I tap that one spot on one bulb again.

Inconvenient to say the least when it's the only light source in our laundry room...

Help?

On 2022-06-04 by InspectApedia-911 (mod) - pair of fluorescent bulbs won't light reliably when powered on

@Thom,

Yep. We had that problem with lights over a kitchen counter in a 1960s home in Two Harbors MN.

FLUORESCENT LIGHT REPAIRS has a lot of detail on this

You may need to
- find a loose connection anywhere in the circuit, but often at the lamp connectors
- replace bad bulbs
- replace a bad transformer
- replace one or more bad bulb contact-mounts

Finally my champion brother-in-law took the task of doing just that and the lights have since worked perfectly.

On 2022-06-01 by matt - where to look for loose electrical connections in mobile home - Fleetwood doublewide

hello i have a 2001 fleetwood double wide that i have lost power to the back 1/4 of my home i checked all the breakers & changed the recepticales on the back half of my house i'm thinking it's a junction box but not sure where to look .

On 2022-06-01 by InspectApedia-911 (mod) - causes of flickering lights in manufactured homes

@matt,

Provided that you've first checked out the obvious and dangerous causes of flickering lights given above on this page,
and we're really talking about an actual loss of electrical power,
then
You could have a bad crossover connector between home sections.

See MANUFACTURED HOME CROSSOVER CONNECTORS https://inspectapedia.com/Manufactured_Homes/Mobile-Home-Electrical-Crossover-Connectors.php

On 2022-04-13 by Robert - water heater makes lights flicker

My lights flicker when my 80amp tankless water heater is running. It is hooked up to my main 200amp service box and the lights are on connected to my inside 100amp box inside.

On 2022-04-13 by Inspectapedia Com Moderator - what else the electrician may check on flickering lights

@Robert,

Your electrician may find some things to check besides the rather lengthy list of causes of flickering lights that we give above on this page, but I hope you will review that list, as it's more complete than I can make up de novo here.

Remember to check carefully the connections on any aluminum wire circuit connections such as may be powering an electric water heater.

On 2022-01-18 by Mahmoud Salem - lights flicker on top floor in building

Hi, The lighting in the top floor flickers and the circuit breaker turns to off. No signs of burns or cut wires. Is the circuit breaker faulty? Took it to shop and was checked and I was told it was ok! Thanks

On 2022-01-18 by Inspectapedia Com Moderator

@Mahmoud Salem,

It could be a bad circuit breaker but more likely is a loose electrical connection, or one of the other causes listed in the article above. Please look through that information and keep me posted.

Also look for roof leaks that wet an electrical box or connector.

On 2021-11-30 by Robert Gillitzer - overheating electrical connections can cause flickering lights

I have one circuit that has several outlets & 3 lights on it. When I switch on any of the lights, or plug into one of the outlets, that one or all, depending if I have more than one light one, all will flicker.The light switches have been replaced, but the lights still flicker.

Is it possible for one of the switches or outlets to affect any or all the connections on that line? Or should I be looking at the main box for a loose connection of that line. All the other lines in the house are ok

On 2021-12-01 by Inspectapedia Com Moderator - loose or overheating electrical connections can cause flickering lights

@Robert Gillitzer,

For sure a loose or overheating connection anywhere on the circuit, from the electrical panel to the light fixtures and receptacles involved could cause flickering lights.

By the way, usually we don't put both receptacles and fixed lighting on the same circuit.

On 2021-11-28 by Warren - sub panel causes flickering lights

i have a separate part of the house that has a sub panel with 4 breakers and from time to time different lights within those 4 circuits goes out randomly and then randomly come back on without tripping any breakers what could be causing this type of problem ?

On 2021-11-28 by Inspectapedia Com Moderator - causes of flickering lights are listed here

@Warren,

Most likely the cause of your flickering lights is one of those described above on this page.

Watch out: there are some brands of electrical panel (e.g. FPE Stab-Lok, Zinsco, and others) and some electrical wiring (solid aluminum branch conductors) for which flickering lights are a big red flag of imminent danger of a building fire.

On 2021-10-29 by James D - TV remote causes flickering lights?

I have a small LED night-light that is plugged into a wall socket in my bedroom.

My question is when I use the TV remote (Fire TV) it makes the night light flicker. Also, when we turn off or on the ceiling fan/light switch, a small table side lamp (that can turn on and off when you touch the base) will turn on if the table lamp is off, and off if the table lamp is on.

I am worried about how our home was wired since the contractor was "El Cheap-o" on materials and labor. Any thoughts or suggestions?

On 2021-10-29 by inspectapedia.com.moderator - problem electrical circuits need more diagnosis

@James D,

That sounds like a wiring error or possibly, if we're lucky, simply a loose electrical connection somewhere on that circuit.

But

Watch out: such connections can be dangerous, causing arcing and overheating.

• How old is the home?
• When was the wiring job done?
• Was the installer a trained, licensed electrician?
• Were aluminum wire or aluminum components used ? (A particular fire hazard for branch circuits)
  

Best would be to get an experienced, licensed electrician to trace and diagnose the problem circuit.

Depending on what she finds, that in turn may be suggestive of inexpert workmanship; if so then further inspection of the home's wiring and electrical panel and devices would certainly be justified.

On 2021-08-23 by dave - dimmer switch makes lights flicker on and off

we turn om lights to the house and lights flicker after a period of time when dimmer switch is on why?

On 2021-08-23 by inspectapedia.com.moderator - look for a loose electrical connection or overheating at a light dimmer switch

@dave,

Of course there could be another problem but the common explanation for the flickering lights that you described would be a loose electrical connection at the switch or an overheating switch. I would have the switch replaced.

On 2021-07-24 by Sully - all lights blink briefly when some appliances run

The lights on all 15a circuits in entire home blink momentarily when HVAC compressor or vacuum cleaner plugged into 15a outlet starts? 20a circuits don't seem to be issue. Blink happens for both L1 & L2 circuits.

On 2021-07-24 by mak.church (mod) - too much current draw for a 15A but not 20A circuit can cause flickering Lights?

@Sully,
In the above article, there are a number of diagnostic steps that are worth looking at. Because of your reference to both 15A and 20A circuits however, pay specific attention to the section:

18 Causes of Dimming or Flickering Lights or Electrical Power Loss at Buildings

and the #2 item there: Appliance or motor drawing high current

Perhaps the high current draw in this case is just enough to blink or dim lights on a 15A but not on a 20A circuit.

A guess is that the two devices you cite are drawing a moment of high current at start-up (not un-common). On a 20A circuit the current drawn is tolerated because the circuit permits a bit more current than the 15A wires;

A corroded or loose connection in a circuit or in a panel might cause that trouble too, but as you're seeing it on both sides of the panel I suspect our first guess is the right one.

Let us know if you have additional questions.

 

On 2021-06-25 by John - worried about electrical wiring in a 1970's home

Hello, i bought a house that had its electrical wiring updated in the 70s. When they did it, they did not dedicate a circuit for each room so some rooms share circuits.

In my small office I had my computer with monitor and when someone turns on the bathroom ceiling light my computer monitor power turns off - it does this consistently.

I am worried because the computer monitor is LED, uses low power and the light bulb in the bathroom also is LED.

I do not have any high intensity applicances on in my room, just laptop, LED monitor and sometimes a fan and light.

Does this indicate bad or wiring that should be replaced? My concern is that the previous owners were very frugal and likely has the wiring done by unlicensed electricians.

On 2021-06-25 by mak.church (mod) - copper wiring doesn't need replacement based on age alone but watch out for aluminum wire

@John,

Except where your electrical wiring was improperly sized in the first place or where it has been damaged by a building event such as a fire, it is quite rare that it is ever necessary or even appropriate to replace the wiring itself. Copper doesn't wear out. Copper thousands of years old has been found intact in the Egyptian tombs.

It could be a problem with connectors, or an overloaded circuit. Simply turning on the bathroom light should be such a trivial load on the circuit but I suspect there is an unsafe connection or switch for which you need an electrician who will locate and fix the connector, switch, or device.

Because it's expensive to bring an electrician to a property for a single small problem, that would be a great time to have the electrician add a dedicated electrical circuit to the room where you use your computer.

Watch out: 1970s electrical wiring could include aluminum solid conductor branch circuit wires. If your home has aluminum wiring and the wiring has not been properly repaired by installing the special connector at each and every connection then that circuit is unsafe and is a fire hazard.

So be sure to have your electrician check promptly for the presence of aluminum wiring. Let us know what you're told.

On 2021-06-26 by John - how do I identify aluminum wiring

@mak.church, Thank you. I think the work done in the 1970s was to increase the amps in the home. I confirmed it was not done by a electrician - instead it was done by a family member who is very handy with homes. (Make me nervous). The home was built in the late 1940s and is a two family. It now has 100 amps per apartment.

Is there anything I can do that would help you identify whether I have aluminum wiring such as taking a photo? I will have an electrician come to check regardless but appreciate an unbiased opinion

On 2021-06-26 by inspectapedia.com.moderator (mod) - check flickering light circuit for aluminum wiring

@John,

Your electrician will be able to tell immediately if there is aluminum wiring in the electrical panel when she opens the panel cover to inspect the circuits inside.

That's not something you should do as you could be shocked or killed.

However if you look at any electrical wiring that is visually accessible you may occasionally see printed on the plastic covering of plastic wire the word "aluminum" which would be significant.

You can also use the on-page search box to search this website for

ALUMINUM WIRING HAZARDS & REPAIRS - overheating or corroded connections can cause flickering lights

For an article describing other wiring text or imprint or size that identifies it as an aluminum product.

From the age of your house, the original wiring would not be aluminum.

On 2021-06-26 by John - electrical outlets have reversed polarity

@inspectapedia.com.moderator, thank you. I will definitely not be attempting to investigate or fix beyond what you suggested. I have a great deal of respect for this things and experienced electrical shock as a child!

I just recalled that when we bought the home we did have an electrician over as part of renovating two rooms. He replaced some switches and install a number of new outlets. He did find two switches quite old that needed replacing. My hope is that he would have noticed the aluminum but I’ll have someone check regardless.

However I believe he did not investigate or check the other rooms in the home as I just checked a number of outlets in these rooms and they have reverse polarization which I know is not usually a big deal but thought to ask if it could have any relation to the issue with my computer.

The outlet the computer and monitor are plugged into has reverse polarization.

On 2021-06-26 by inspectapedia.com.moderator - investigating causes of flickering lights - don't forget to check for aluminum wiring

@John,

Thanks for the added detail; keep us posted;

Certainly some of my warnings will err on the side of safety.

See USING an ELECTRICAL RECEPTACLE TESTER to CHECK VOLTAGE & WIRING

Watch out: an electrical receptacle with reversed polarity can be unsafe and in some cases can damage electrical equipment. It may not be obvious, after all it's "alternating current" running in "two directions" on the circuit, between hot and neutral.

But keeping the neutral side "live" as what happens in reversed-polarity circuits can actually damage some printed circuits and control boards by delivering power where it is not expected to be fed.

On 2021-06-16 by Cori - expensive bill for fixing flickering lights

I have flickering and dimming lights thought out the whole house. Electrician is here now.

He is replacing my outside main wire and will replace 3 or 4 breakers on panel but says it' NOT GUARANTEED the flickering and dimming lights will stop. R u kidding me?? I'm paying him $1850.00!

On 2021-06-16 by inspectapedia.com.moderator (mod)

@Cori,

Before the electrician leaves ask him to observe whether there are any flickering lights and ask him if there's something else that he recommends

On 2021-05-24 by Zach - Whenever I turn my kitchen light on my dining room fan/light combo dims.

Whenever I turn my kitchen light on my dining room fan/light combo dims. It stays dim until I turn kitchen light off. At first I thought it was possibly in the switch as it's a double switch with power hooked to the top that controls both the top and bottom switch. There is also a 3way switch in the same location ran on a separate breaker.

I turned off both breakers took both the dining room light and kitchen light off the switch and hooked each one directly to the power feed with wire nuts. One connected to one circuit and the other connected to the circuit that the 3way had been on. I flipped on one breaker and dining light came on. I flipped on the other breaker and kitchen light came on.

Again dining room light dimmed as before. I've checked and tightened all wiring going to both fixtures. Help!

On 2021-05-24 - by (mod) - Whenever I turn my kitchen light on my dining room fan/light combo dims

@Zach,

That sounds like a shorted electrical circuit, switch, or fixture.

Your electrician will probably use a DMM or VOM to check for shorting and check the current draw on each of those circuits and also she'd inspect the electrical panel itself, the breakers and the bus - for arcing.

Is there aluminum circuit wire in the building?

What's the electrical circuit brand?

How old is the building?

On 2021-03-21 by Vernon - had a circuit that controlled 3 outside motion lights fail.

Recently I had a circuit that controlled 3 outside motion lights fail. I checked for proper voltage at the switch and got "0" voltage reading. Then I checked for voltage at the circuit breaker and it measure 117v.

Then two days later I'm assuming the same or neighboring circuit failed which controls 5 outlets which have a washer, small firdge, garage door opener, and some small devices.(6outlets) I noticed that all of these circuits arent even isolated to certain areas of the house , they seemed to be mixed up.

this house was built in the 60's with what appears to me as some renovation along the way with poorly added circutry. 3 years prior to all these issues dimming of lights when washer and or dryer is in use, as well as bzzing in swiches was present.

Any comments as to what the next step or solution to this problem would be is greatly apreaciated.

On 2021-03-21 by (mod) - outside motion light circuit failure

If that were my home I'd have a licensed electrician trace the circuits involved, both to find the arcing or loose connectors, other unsafe connections and devices, and/or to get clear on what's wired on what circuit: we may need to add circuits to correct an overloading problem as well as fixing the wiring problems.

On 2021-03-24 by (mod) - Unsafe wiring, flickering lights, lost neutral, bootleg ground, moisture damage in a tropical environment home

This diagnostic discussion has moved to its own page

at FALSE GROUND, BOOTLEG & FLICKERING LIGHTS

...

Continue reading  at FLICKERING LIGHTS, LOST NEUTRAL, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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