Building humming noise troubleshooting: causes & cures.

Diagnose, & Cure Humming Noise Complaints. What are the common sources of a humming sound heard in or near buildings?

Which humming noises indicate that repairs are needed? Cures for building humming sounds.

Page top photo: hot water heating system circulator pump noise ranges from near silent to a constant humming depending on the pump brand and its condition of repair. A humming noise that occurs during the heating season or when a tankless hot water system is in operation might be traced to one of these.

Humming Sounds in & Near buildings

Humming noises, also described more often as buzzing, occur at failing relays such as the relay in a heating system or air conditioning system or controls for circulator pumps.

Just about anywhere that an electric motor, electric relay, or low voltage transformer is used inside a building or its equipment there may be a humming sound.

Humming noises outside of buildings are often traced to a power transformer located on or near the property and of course don't rule out nearby equipment on adjoining properties. Even power lines can produce a humming sounds.

Humming sounds around air conditioner compressor motors, fan motors, well pumps or other motors may be normal if the motor is running, but may also indicate a motor that is unable to start.

Photo: the outdoor compressor/condenser unit of an air conditioner or heat pump may run continuously depending on weather conditions and is a common source of noise complaints. Don't forget to consider rooftop-mounted HVAC equipment or equpment whose noise may be transmitted through a building's ductwork or piping.

Don't' rule out medical causes of perceived humming sounds in and around building.

Here is a list of suggestions for tracking down and fixing a humming noise problem in or at a building. Step through this list and then don't hesitate to use the page bottom COMMENT BOX to post follow-up questions as needed.

• Is it Humming or Buzzing:
  
  because some people describe buzzing noises as humming sounds, or vice versa,
  
  Also see BUZZING NOISE DIAGNOSIS
• CIRCULATOR PUMPS & RELAYS - Circulator pumps on heating systems
  and at
  
  CIRCULATOR PUMP WON'T START where we discuss jammed circulator pumps can be sources of humming in buildings where hot water heating is used or where a circulator pump is used for an indirect water heater.
• COMPRESSOR CONDENSER NOISES - Compressor motors on air conditioners or heat pumps.
  
  In our HVAC noise articles we describe a wide range of sounds: squeaks, hums, clanks, squeals, bubbling, hissing, etc. Humming or chattering noises (rapid clicking) at the air conditioning compressor/condenser unit may mean that a contactor or relay is failing - the unit makes noises but won't actually start.
  
  Details are at
  • HARD STARTING COMPRESSOR MOTORS
• CONDENSATE PUMPS on air conditioners, heat pumps,
  
  and STEAM CONDENSATE PUMPS may hum if the motor is having trouble starting.
• Contactors and relays
  
  found on heat pumps and air conditioners and in some furnaces or even hot water boilers may emit a humming noise if the relay is worn, dirty,or damaged.
• ELECTRIC MOTOR NOISE DIAGNOSIS
  
  Humming sounds heard in a building might be traced to any electric motor both in normal operation or particularly at motors that are having trouble starting.
  
  Also see
  • CAPACITORS for HARD STARTING MOTORS
  • ELECTRIC MOTOR DIAGNOSTIC GUIDE
• Electrical field-caused noises:
  
  some metal objects or equipment including above-ground or buried metal piping may respond to 60-cycle electrical field-induced vibration where piping passes below electrical power lines.
  
  Field example: in the 1970's we found that stopping our dirt-bike motorcycle below the Fishkill N.Y. power distribution line and turning the metal handlebars at right angle to the direction of the overhead power lines could on occasion cause an easily-felt vibration to be induced in the motorcycle handlebars. Loose equipment or connectors on the handlebars might even buzz in that position.
• Fans & blower fans 
  
  in furnaces or air conditioners produce motor noises in normal operation but can produce a hum if the motor is jammed or failed. See our Electric Motor Noise article listed above. Also see
  • HVAC NOISE-2 CHATTER CLANK FAN GROAN - chattering, clanks, clunks, cyclical, fan, groans, growls, honking
• Gas regulator humming or hissing noises
  
   range from probably harmless (some humming sounds at a gas regulator) to very dangerous (hissing of a gas leak).
  
  See GAS REGULATOR NOISES for details about the sorts of noises found at gas appliance regulators.
• Ground Humming noises coming from the ground:
  
  loud booms, moaning, humming, and other sounds coming from the ground may be due to tectonic plate movement.
  
  See Sinkholes in GEORGIA
  
  Also see BANGING BOOMING NOISE DIAGNOSIS & CURE - home
  
  
• HVAC equipment humming noises:
  
  See HUMMING NOISES from HVAC SYSTEMS sounds from A/C or Heat Pump system condenser or air handler

Photo: a tricolored bee photographed by the author in Two Harbors, Minnesota.

• Insect Noises:
  
  We've traced some humming noise complaints to a bee infestation, such as honeybees nesting in a building wall.
  
  See HONEY BEES in BUILDING WALLS and also
  
  See INSECT NOISES in BUILDINGS
• Transformer Humming noises:
  
  electrical power transformers from a wide range of uses may emit humming, buzzing or "vibrating" sounds. Examples include pole-mounted or on-ground or even under-ground power transformers or in buildings, smaller transformers used in the operation of HVAC equipment.
  
  See LOW VOLTAGE TRANSFORMER TEST - Humming and also buzzing noises are also found at low voltage transformers. A low voltage transformer may continue to put out the required 24-Volts but may keep up a humming noise for months or years. I prefer to replace such devices.
  
  Before you blame the electric motor: if you turn off power to an electric motor that you think is the hummer, such as an air conditioner compressor/condenser unit or at a heating furnace, and if you are still hearing humming, find and check the low-voltage transformer. Often an aging transformer will put out an annoying humming sound.
• Water pump humming noises,
  
  involving an electric motor, are generally rather noisy - a motor noise may shift, however to a more quit hum if the motor is jammed or if the motor is having trouble starting. A
  
  
  • See our ELECTRIC MOTOR NOISE DIAGNOSIS. Also see
  
  
  • PLUMBING NOISE CHECKLIST where we discuss water pump noises
• WINDOW LEAKS INTO BASEMENT or other leaky windows can occasionally be a source of wind-generated humming sounds

Relate Building Humming Noise to Equipment Operation, Weather, Time of Day, etc.

See

• SOUND EVENT LOG a web article including explanation of what information should be recorded to help track down the source of building sounds & noises

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2024-08-09 by Anonymous - Constant mechanical hum in top floor of building - started in August

Hello. I moved into a top floor unit 8 mths ago. No humming / vibration sound then yet from April to now

[Now] (August) there is a consistent mechanical like hum that only breaks for a second or three and sometimes goes continually.;

It's a low vibration like / sounds similar to a motor running on lower sound.

My real estate sent an electrician out & he heard nothing. The external noise that day was a lot in the neighbourhood and it’s distinctive at night I have to turn my tv up louder than I like and early hours of the morning it’s hums hums hum feel it with my head on the pillow.

They tell me (real estate) nothing they can do.

I feel some checks should be done yet I’m unaware how to find the source myself or what checks may need doing? Any advice I’d be so appreciative - Anon 2024-08-09

On 2024-08-09 by InspectApedia Publisher (mod)

@Anonymous,

Forgive the delay in not responding immediately - I needed to give your question some thought - I'm not as fast as AI but perhaps more complete and certainly more human.

The timing of when this noise began is often a diagnostic aid. It sounds like you moved in during cold weather and now of course when it's hot and humid it's possible that air conditioning or cooling equipment or compressor somewhere is running continuously that was not running previously.

The fact that you are on the top floor means that you are right below any mechanical systems that are mounted on the roof.

So it seems to me that an inspector ought to take a look up there to see what's running.

I would be looking for equipment that's operating anywhere near your floor or in locations whose sound could be transmitted to your floor, such as through a stairwell or elevator shaft or HVAC equipment, that is if I were inspecting a building and a complaint such as yours. You need to listen for someone willing to do that when you're trying to get help..

It's also important for investigators to recognize that people's sensitivity to noises at different frequencies varies quite widely and that just because someone you ask for help doesn't him or herself say that they hear the noise isn't a complete diagnostic.

For completeness I mentioned that sometimes we need to check with our doctor as well to make sure we don't have a hearing or neurological problem.

This page is our index to our articles on finding tracking down and fixing huming noise complaints. You could look through this article list for some suggestions.

You say the noises continuous but breaks briefly. It might be worth keeping

a SOUND EVENT LOG that can help trace an annoying hum to specific equipment.

Separately at SOUND CONTROL in BUILDINGS

we provide a series of detailed articles on noise or sound transmission control - that might be helpful for you too.

Daniel

On 2023-07-18 by Barri Anne Brown - Regular Cyclic low-frequency hum/vibration from a wall between us and neighbor

After 2 years, I have a new cyclic low-frequency hum/vibration as of April, emitting from one wall. We're not sure if it's tenant or building related, but we can't find the source, and it happens pretty much only 12 am - 7 am (tenant?).

We've asked as much as possible, can find nothing. Opened the wall, saw nothing. I can't sleep. The cycle is maddening: 10 seconds on, 30 seconds off pretty much, sometimes louder, sometimes softer. Subtle low-frequency hum but the vibration when it cycles goes through my bed and once it starts I cannot sleep over it. I even took a decibel reading -it's not loud but the cycle is pretty exact on and off.

Any clues as to what it might be? It's definitely in the building, not outside. And runs along the length of one specific living room wall. Next is call the police (!) or spend $$ on noise consultant :(. Thanks!

Reply by InspectApedia Publisher (mod)

@Barri Anne Brown,

Very regular cycling on and off of a noise usually points to some equipment operating somewhere nearby that is in turn being controlled by some external control - a timer, a sump pit float, a pump, etc.

So the combination of keeping a noise log of when during the day you hear the noise and a review of all of the equipment in or near the building should help you track down the sound.

Keep us posted - what you find will help other readers.

On 2023-01-05 by Craig Loud humming motor noise indoors, also barely heard outdoors starts at 2AM

I hear a humming like a low motor running. It is loud in the house but can still be heard outside but barely.

It seems to start about 2-3 am and runs until about 4-5 pm and sometimes does not stop off for days. I have shut all the power off coming to the house and have no other electric or motor items near the house to cause anything like this. Im on a rural property with the nearest neighbour 1 mile away, with no sound or vibration coming from their place. Any ideas

Reply InspectApedia Publisher (mod)

@Craig,

If you hear the noise when power is off to your house that sure suggests that it's not any of your own equpiment.

Low frequency sounds can carry great distances, especially depending on wind, temperature, and other varying conditions.

If when you hear the noise you step outside and the noise is louder that's a clue; walk away from your house, towards the noise.

If it gets louder it's probably not related to your house at all.

Note local conditions like wind and temperature.

Neighbor is harassing me with noise - no sound insulation between attached buildings

My neighbour is harassing me, He has a electrical standing fan that he has resting up against his wall on the other side. Our buildings are attached but uninsulated. I have environmental health and their recording equipment and that can't pick it up si my son and I ate are not getting any sleep for 2 years please please please tell me I can get some help. Thanks - On 2022-05-07 by Penny -

Reply by Inspectapedia Com Moderator (mod)

@Penny,

If you're not getting help by polite appeal to the neighbour to move his fan, an dif your local building management won't help, and if your local health officials are not able to intervene, then what's left, short of moving, is to install a sound-insulating barrier wall between yourself and your neighbour.

Details are at

SOUND CONTROL in BUILDINGS - home

SOUND CONTROL for WALLS

SOUND ISOLATION STRATEGIES

Take a look at those articles and let me know if you have more questions and we'll be glad to try to advise you further.

On 2020-08-22 by KM - Pulsing Sound every second, all day long

I live on the 14th floor of a 15-story bldg. I hear and feel pulsing, about 1 per second, in my apartment 24/7 and it is strong behind my walls.

There is a huge unit on the roof of the building and when I touch one of the pipes coming out of the unit, I feel the same pulsing there.

The pipe is cool to the touch. I would like to know what is causing the pulsing noise/vibration. Is this something to worry about? And is the noise/vibration fixable? Thank you.

Moderator reply: check the equipment for proper operation then go to sound and noise isolation steps

KM,

It certainly sounds as if you've traced a pulsing noise to rooftop HVAC equipment or a rooftop pump. Such noises or sounds may be normal for the equipment OR it might mean that the equipment is having an operating problem and is about to fail.

You'll want building management to check that the equipment is operating properly. If it doesn't need repair then there's work to do to sound-isolate the piping or ductwork between that equipment and your apartment.

See SOUND ISOLATION STRATEGIES

Humming Noise Complaint & Solutions at a Pump

Researched this already ad nauseum online, but thought to relay for amusement and to document with for myself. Hoping for quick resolution from afar (and far beyond my control).

I very recently became aware of a persistent hum in northwest corner of my room (rooftop pre warish fireproof building,surrounded on three sides by terrace - exterior walls south, west,and north now mostly/all sheet rock (mold resistant I hope).

I thought it might be a ceiling fan or fridge against wall on floor below it seemed to fade and even shift. Concurrent banging made me hope it was plumbing/boiler/hot water pump, etc. related and would soon be repaired. Could it be a circulating pump in basement that is straining to provide hot water pressure notoriously absent at times?

The HUM was deafening last night in the NW corner, but it completely shut off last night at about 11:40pm very dramatically and now seems at low volume -hard to tell in the daytime...with the tv on :)and all the hard/software buzzing.

The HUM is low/mid frequency - seems 50% audio/50% vibration. I may still order compression pads to use under the bed legs with blocks of hardwood. One idea may be to use audio spikes for bed legs. I say the more high quality rubber you can lay down, the better. - On 2019-02-12 by Anonymous (by private email)

Moderator reply: humming noise traced to rooftop mounted pump that needed a sound isolating pad

Indeed Anon, we're in the same hum-along camp.

Two nights ago at 2AM I was on my rooftop in my pajamas checking to see if the humming noise that woke me up was a water pump that should not have been running.

We're using a Scala-2 water pressure booster pump WATER PUMP PRESSURE SENSITIVE - https://inspectapedia.com/water/Water_Pump_Pressure_Sensitive.php

I mounted the pump on a rubber pad to reduce noise transmission through a (concrete) roof into the building below.

From our plumber I have had some reports of Scala2 noise and intenal bearing failure that might be factory defects, or maybe not.
If someone were foolish enough to leave water running in an unattended building for more than a month where a Scala2 was installed you might see pump bearing wear leading to a noisy leaky pump. (Not to mention the water waste and water bill).

Humming noise frequencies combined with factors like noise transmission through building materials can make tracking down a humming sound difficult - and that's before having checked with one's doctor about an ear problem or a neurological problem.

Examples of humming noise transmission in buildings

A pump anywhere in a building can transmit noise through piping. I include not just water pumps but any pump and in fact many other electric motors. Some examples include

• oil burner pump transmits vibration to a ceiling or wall through oil piping
• hot water heating circulator transmits humming through heating pipes
• water pump transmits humming through water pipes
• failing furnace air hander or air conditioner air handler blower motor transmits humming and vibration through metal ductwork
• sewage ejector pump or sump pump transmits vibration through drain piping

Noise traced to oil burner operating trouble - WM Gold Model P-W60-4 Series 3 oil burner

I have a WM Gold Model P-W60-4 Series 3 oil burner. Installed about 2005 by a contractor when adding an addition. Only problems were mostly due to ,clogs tanks being from 1957.Its had regular servicing by local companies.

Recently, about 2 weeks now when our burner goes on, after a few minutes we get a muted horn like noise coming through the house loud enough to be noticed as not normal. Sometimes changing in pitch. At the furnace you couldn`t hear it then.

But above it and in even the farthest room from it you can hear it I suppose transmitting through the radiators?When it stops running the noise stopped.Seems to run fine and works.

Anyway on 1/ 9 I had the regular serviceman come and he cleaned it, changed the filters, changed the nozzle(12570B) , and the cartridge filter on the tanks. Everything seemed good, no excessive dirt on filters, but he said as he undid the cartridge on the tank it seemed like pressure escaped?

Flow was good from tank to unit at filter. Turned it back on and now the noise was heard near the unit plus upstairs. It even remained some seconds after the unit was shut off. He then changed the blower unit. No change.

Do you have any ideas on what might be causing this?Or previous cases of this happening?

He said it might be expansion noise or the boiler or control. But basically he was stumped.

I was told to make sure the gauge didn`t go over 180, and to try asking WM support.

We are concerned this might be a precursor warning to a part failing, but everthing seems to be working.Any ideas? Thanks. Regards Thomas - On 2016-01-11

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