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Buzzing aquastat relay © D Friedman at InspectApedia.com Heating System Buzzing Noise

Diagnose & cure buzzing & vibration noises

Diagnose & fix buzzing or vibration noises at heating equipment:

What are the causes of buzzing or vibration noises at heating equipment like boilers, furnaces, or water heaters? How is buzzing noise found and fixed?

This noise control article series discusses the diagnosis and cure of heating system noises, including heating equipment noise, heat piping or ductwork noises, radiator noises, steam pipe banging, and steam radiator vent noise control. We describe just about every single noise that might come from or have to do with building heating systems.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

Heating System Buzzing or Vibration Noise Diagnosis & Cure

Buzzing aquastat relay © D Friedman at InspectApedia.com Watch out: while adding sound control barriers and insulation around a mechanical room be sure that you do not interfere with proper combustion air supply or you risk making the heating system work poorly or you may make it unsafe, risking carbon monoxide production and even death.

Buzzing sounds and vibration at oil or gas fired heating boilers, furnaces or water heaters can be caused by a variety of problems such as a control cover touching a relay switch, control unit transformer failures, bad motor bearings, or loose mounting hardware.

Buzzing and similar vibration sounds may also be traced to fuel oil piping that is not properly mounted, is in contact with building surfaces, and is transmitting vibrations from the heating appliance or oil burner to the building.

If an electric motor is vibrating, normally or because of wearing bearings, its vibration is easily picked up, transmitted, even amplified by metal parts like ductwork or fuel piping.

We might also trace buzzing sounds to a failing low voltage transformer such as the transformer that may power zone valves, thermostats, and some other heating system components. [Blue arrow in my photo]

Buzzing heating system control relay switches also can be quite noisy. our photo illustrates how a trapped aquastat relay buzzing problem can happen. Our measuring tape is stretched across the two steel ends of the aquastat control.

The red arrow in the top center of our photo points to a relay in this control.

The edge of my yellow measuring tape that is closest to the top of the relay is also tight against the steel ends of the box that contains this whole control.

When the control box cover is installed, from the location of the edge of my tape right above the relay top, you can see that there will be very little clearance between the relay's moving head and the an aquastat control cover that is pressed tightly in place.

Index to Heating System Buzzing Noise Diagnoses

Buzzing vibration noise at chimney when furnace runs

Reader Question: how to find cause of buzzing noise near chimney

I came upon your website and typed in a question but I don't know how to do these things; I couldn't tell where/how to get the answer. I found this e-mail address to try and hope someone will get this.
I am an old lady living alone, so contractors take advantage. This past winter the furnace made loud buzzing/vibrating noises when firing.

The service person said it was air in the pipes, which it wasn't. I called another after everyone said he was full of it. The next company owner said my firebox hadn't been cleaned out properly for years and was falling apart.

The noise was due to all the ash and the change in loudness (louder the lower the outdoor temp got) was due to the air density changing with the cold. He said the firebox was so plugged up that it couldn't get enough air. The furnace was about 30 yrs old, so I thought that a new part sounded reasonable.

As the weather got warmer, it no longer made the noise. But I had the new heating coil & firebox installed. It started making the same type of noise again sometimes when the furnace fired, not as loud as last winter, but getting louder now. Of course when the guy came back to look it didn't make the noise.

The noise (previously and now) is not audible when standing next to the furnace. You hear it when you walk far enough away from the furnace parallel to the chimney. On the first floor, the noise reverberates all over. There are 2 fireplaces and it seems like the noise vibrates out from them.

Now the guy says this reverberating noise can be cured by inserting something (snake?) into the oil line. He claims the oil line makes a pneumatic vibration. I have looked at numerous websites and see nothing like this. All claim that the kind of noise I have is bad or loose bolts, motor blower, etc.

No one mentions an oil line causing a noise. I would greatly appreciate an unbiased opinion of this situation. - Anonymous by private email 2017/09/09

Reply: safety checks first: check the chimney and furnace area for signs of a fire or dangerous smoke

Carpenter Bee closeup photo (C) Daniel FriedmanWhen a furnace makes loud buzzing/vibrating noises when firing I would look for things in order of safety first.

That's why I said to look at and smell around your heating system. If you see fire or smoke turn the system off and call 911.

If the noise is actually in the chimney that could indicate a burner that is not operating properly - and is unsafe.

Watch out: I an extreme case a noise in a chimney could be a chimney fire: you'd know this (and run the hell outside and get away from the house and call 911 fire department) if you heard a roaring in the chimney and saw smoke pouring out of the chimney top.

Otherwise we're looking for an experienced service tech who can think clearly.

I'll suggest some more possibilities below that might help you interpret what you're told and also to ask some questions.

Ultimately you want to say to the technician: ok so SHOW me the part that is causing the trouble and explain to me in plain english why it's doing that.

See details at CHIMNEY NOISE DIAGNOSIS

Key Step: Ask for a Senior Service Technician

Call your heating service company. Talk politely and without sounding like you're making trouble, to the service manager.

Say Look, we've had repeated service calls, my system isn't working right and it might be unsafe.

Please find your senior, experienced, sharp service technician and ask him or her to come over here and help sort this out.

More opinion about trouble tracking down the buzzing vibration sound

I don't assume that the heating guys who disappointed you are necessarily crooks. More often they're either incompletely trained or they know stuff but were not English majors in school.

First: what do you have? "Furnace" means forced hot air heat. "Boiler" means forced hot water or steam heat. Calling equipment by the right name cuts back on the nonsense the techs might try to tell you.

Also an air heat system has different parts so we'd look in different areas for noises than at a boiler.

A dirty or poorly-cleaned or poorly-adjusted system might rumble or roar or smoke but buzzing usually is traced to

Vibration can be picked up in sheet metal (ductwork of an air system) or water pipes (in a hot water heating system) or in the fuel line if it's an oil fired burner at a boiler or furnace.

Sometimes by pressing on a suspect pipe or oil line the noise will change or stop - that's also diagnostic.

See OIL LINE BUZZ & VIBRATION CURE for a discussion of the causes and cures for buzzing and vibration that seems to come from the oil piping itself.

Now: vibration might be "normal" - all motors vibrate a little bit.

Or it might mean that a motor bearing or part is wearing out.

If the noise is "normal" it might still be "loud" if the vibration is being picked up by piping, tubing, ductwork that conduct noise and even amplify it in a building.

Let me know what you're told next and perhaps I can suggest some follow-up questions.

 

Heating Control Device or Relay Noise Buzzing Sources

If the control cover is lightly touching the relay switch the control may simply buzz when the relay is trying to move.

On some controls this clearance is so tight that the relay or is trapped solid so that it cannot move - leading to a no-heat service call.

So if you notice that the control cover on your aquastat (or on a cad cell or stack relay) has been bent slightly convex, or has been left slightly ajar (our photo, above right) think twice before jamming it on tightly. Thanks to oil heat service technician Bob at Bottini Oil for this service tip.[3]

External causes of buzzing chattering relays in heating system controls such as aquastats or limit switches include

Separately

at RELAY CONTROL SWITCHES

we give an exhaustive list of all known causes of chattering, humming, buzzing, or clicking relays including those found in heating or air conditioning system controls.

Cad cell control or stack relay buzzing or jamming trouble: if you hear or have ever heard buzzing from any heating system control that includes a relay switch, watch out for a control cover that is in contact with a relay switch in the unit. If the cover is lightly touching the relay switch the control may simply buzz when the relay is trying to move.

But a too-tight control cover can also prevent a relay from operating, leading to loss of heat. Simply pulling off the cover to let the relay move freely can immediately discover and "fix" this problem. Details and an explanation are

at HEATING SYSTEM NOISE DIAGNOSIS

and at CAD CELL RELAY SWITCH

Heating Equipment Buzzing Noise from Gas Burning Equipment, LPG or Natural Gas

Boiler (Hot Water Heat) Buzzing Noise Sources

Webstone differential bypass valve to address hot water heating piping noises - from Nibco, cited & discussed at InspectApedia.com

Above: a Webstone Differential Bypass Valve that may be sued to reduce heating piping noises traced to excessive and uneven pressures in the hot water (hydronic) distribution system.

Hot water heat buzzing sounds may be traced to equipment or controls.

Earlier on this page we listed buzzing noises relays or other electrical controls that can be found on any heating system.

We have also described noises that may be peculiar to the type of heating fuel: oil vs gas vs electric.

But if your heating system is a boiler remember to also check for failing circulator motor, impeller, bearings. Remember that metal piping for hot water heat, like that of copper heating oil piping, can transmit vibrating noises quite some distance from the actual noise source.

Hot water or hydronic heating system noises may also appear in the heating water circulating piping itself, more-likely at large or tall buildings where the volume, size, and routing of the heating water distribution piping makes significant pressure differences more likely.

On residential and small building heating systems look for

Resources

Electric Heat Buzzing Noise Sources

Watch out: regardless of whether your electric heat is an electric furnace, electric baseboard heat, an electric fan convector or other type of electric heater, buzzing noises can in some cases indicate a very dangerous condition: a hissing, crackling, buzzing noise may be emitted by shorting electrical wires.

Because of the risk of fire or electric shock, such noises mean the system is unsafe and should be turned off at the electrical panel immediately.

Other buzzing noises at an electric heater might be, for forced air electric heat, such as used as backup heat on some heat pump systems, may be traced to blower fan or motor or control relays as we have mentioned earlier in this article.

Furnace (Warm Air) Heat Buzzing Noise Sources

Earlier on this page we listed buzzing noises that might occur in or be transmitted by air duct systems, particularly metal ductwork.

And as for hot water heat, we have also described noises that may be peculiar to the type of heating fuel: oil vs gas vs electric.

But if your heating system is a warm air furnace, remember also to check the air handler blower assembly, motor, fan, bearings, even the door to the blower compartment, for buzzing noise sources.

Also see ELECTRIC MOTOR NOISE DIAGNOSIS

Heat Pump Buzzing Noise Sources

In this article we've already mentioned some buzzing noises that might explain a buzzing heat pump.

Let's separate the general heat pump buzzing noise source first into two categories:

  1. Buzzing Noises from the Indoor Air Handler on a Heat Pump System

    Buzzing at the indoor air handler is likely to be one of those we discussed earlier for forced-air furnaces, such as problems at the furnace blower assembly or motor, or possibly a buzzing control relay.
  2. Buzzing Noises from the Outdoor Compressor/Condenser on a Heat Pump System

    In addition to looking at electrical controls, relays, and noise transmitted by the refrigerant piping, topics discussed elsewhere in this article, look and listen closely for buzzing noises at the compressor motor - signs of a failing motor or a motor that cannot start.

    Watch out: if the heat pump (or air conditioning) compressor motor is buzzing and not starting, (or humming), turn it off immediately to avoid further damage.

Also see ELECTRIC MOTOR NOISE DIAGNOSIS

Heating Equipment Buzzing or Vibration Noise From Oil Burners

Common sources of vibration or sources of buzzing vibrating sounds in or close to an oil burner include:

Also see ELECTRIC MOTOR NOISE DIAGNOSIS

Heating Equipment Buzz or Vibration Noise Transmission via Air Ductwork or Heating Oil Fuel Lines

First try simply pressing on a suspect oil line to an oil burner or on ductwork near the air handler of a furnace. If the buzzing or vibrating noise diminishes or stops you are probably close to the noise source.

A heating oil fuel line fastened to the underside of floor joists over a basement and using simple metal strapping might be using the whole floor structure as a speaker amplifier.

Sometimes we use a mechanic's stethoscope to try to isolate noise right to a specific component. That makes sense if the buzzing or vibration is so horrible that we think there is a component that's failing: replace it before you suffer loss of heat, loss of hot water, loss of air conditioning, etc.

But normal vibration can also be noisy if transmitted to pipes or ductwork.

We can often correct that problem by using noise isolating fasteners to secure fuel oil piping or for duct vibration we might simply tape loose duct parts with adhesive foil tape.

See OIL LINE BUZZ & VIBRATION CURE for details about buzzing and vibration from oil heating equipment oil lines & piping.

Also see OIL TANK PIPING & PIPING DEFECTS if the noise is coming from or being transmitted by fuel oil piping

See AIR HANDLER / BLOWER NOISES for a discussion of noisy furnace or air conditioner air handlers or ductwork noises such as air leaks, clicking, thumping or banging duct noises, fan noises and vibration dampener noises or rattling at fan motors

See DUCT SYSTEM NOISES rattling & buzzing from loose components, if the noise is coming from or being transmitted by ductwork.

Watch out: Buzzing, snapping, crackling, popping - may be dangerous electrical switch or breaker indicators. Buzzing also occurs at failing or failed relays such as the relay in a heating system aquastat or circulator controller or in relays used to control HVAC fans, blowers, and compressor motors.

Buzzing noises from HVAC equipment like air conditioners, heat pumps, heaters are described further

at BUZZING SOUNDS sounds from A/C, air conditioners, heat pump or inverter or from other equipment in, or, or near buildings

Buzzing noises from water heaters are also discussed

at NOISE, WATER HEATER

Curing or controlling noises traced to building heating systems is divided naturally into two topics that should to be addressed in this order

  1. Identify the source and cause of noises traced to the heating system or its components.

    Some heating system noises are normal and are thus not a worry.

    But other heating system noises (rumbling, buzzing, banging) might be a sign that the heating system needs repairs, that it is not operating efficiently (costing more than necessary for heat), or the heating system may be unsafe.

    To rule out heating system operating problems, review the Heating System Noise Cause Diagnosis Articles we list just below in this document.
  2. Isolate heating system noises, or prevent heating system noise transmission through the building.

    Once we are confident that the heating system noises themselves are normal, we can focus on keeping those noises out of the rest of the building. You will still need to identify specific heating system noise sources, since some noise control steps focus on specific heating system installation details.

    Once those noise and sound problems have been addressed, normal building noise transmission and sound control measures, such as sound insulation, can be applied to the room where heating equipment is located.

    See HEATING SYSTEM NOISE & SOUND ISOLATION

Question: oil boiler vibrates loudly when first comes on

2020/01/21 John said:

When heating comes on in morning the boiler (oil) intermittently vibrates loudly for 5 minutes, only up to 5 secs per vibration.

When on does not vibrate when lighting up burner nor when running or when turned off. Can you advise. thanks -

This Q&A were posted originally

at OIL BURNER NOISE SMOKE ODORS

Reply:

John

That sounds to me as if the oil burner needs service/repair

. I can't get enough from your question to have a clear diagnostic opinion but it sounds as if you are saying when the heater has been off for at time and is first trying to run, the oil burner motor is making a loud vibrating noise during start-up. The noise goes away once the burner is running.

The problem could be as simple as a dirty oil burner nozzle or burner electrodes that are soon going to be cruddy enough that the burner is simply going to turn off on SAFETY and won't run at all until the reset button is pushed.

The service tech will of course also check for sources of vibration such as a loose motor mount or even an oil burner line that's transmitting normal burner vibration into a noise transmitted loudly by contact between oil line and the boiler or furnace jacket or against a nearby wall or ceiling

See also

Question: the oil burner rumble, vibrated, & the house smelled like truck exhaust

(Sept 29, 2017) Jessica said:

Had the Miller oil furnace tuned up. The tech replaced some parts and the furnace seemed to be working fine when he left.

A week later I turned it on for the first time, it rumbled a bit loudly, vibrated more than usual, the house smelled like truck exhaust, and then it switched off, I believe from overheating because the panel door was very warm for the short time the furnace was on. Naturally this happened at 6 p.m. on Friday.

The windows are all open now for fumes. Any ideas?

Reply:

It sounds to me as if the oil burner is not operating properly. You did the right thing to turn it off and leave it off. It's time to call your service technician to ask him or her to return to correct the problem. There are many possible causes, of which a few examples include an air leak in the oil piping, or an incorrectly installed nozzle, or combustion air problem.

Below we continue with a catalog of sources of oil burner buzzing or vibration sounds.

Buzzing Oil Burner Question: Oil Burner Noise: loud buzzing, vibrating sounds

I have a Riello oil burner which makes a steady noise on and off when heating is on but all of a sudden the steady noise is much louder like a loud buzzing/vibrating noise...any ideas what it could be ? - Kerry

(Dec 24, 2012) Fred said:

My Aero burner was burning loud, with a lot of flapping on the chimney air valve, furnace was stored for 6 years before I installed it in my garage. I took the nozzle and electrodes out, cleaned them up and reassembled the gun with the electrodes exactly the way they were.

I primed the pump and re-connected the wires properly, but the furnace does not fire now. It runs for a minute, then shuts off and turns the red light on. I can use a little help here

Reply: check these things:

Kerry,

Provided that you can rule out oil burner noise caused by a dirty or misadjusted flame and actual burner operation, there are several common sources of mechanical noises in oil burners too.

This is a good application for an inexpensive mechanic's stethoscope. That device includes on the sensing end a metal rod whose end you can touch to different parts of a motor or assembly to see where vibration is loudest.

Common sources of vibration or sources of buzzing vibrating sounds in or close to an oil burner include:

Let us know what you find, what we learn will help others.

For buzzing traced to an oil line or transmitted by the oil piping,

see OIL LINE BUZZ & VIBRATION CURE

Grant 50/90 heating boiler ran out of oil, trouble getting started, now buzzing, won't fire

hi i have a similar issue to clark as above i have a grant 50/90 boiler which ran out of oil and was filled and bled as normal it took a while to start but was running for 20mins then cut out

i went to press the red reset button and it started making a buzzing noise and now will not fire on its own

i have to press the reset button 30-40 times it will fire for another 20 minutes as normal but cuts out again any ideas on whet i have to replace or check? thanks - Clinton 2/5/12

Reply:

Clinton,

I can only guess from your note, but if a heating system runs out of oil, it's common to have to bleed air from the oil lines and filter and oil pump unit to get it working properly again. If the air-bleed-out was incomplete you may continue to have operating problems.

A second problem is that often when your system draws that last bit of oil from the tank it may suck along sludge and crud that then clog up the oil filter or nozzle. Sounds as if you need a service call. Be sure to tell the tech you had just run out of oil before these problems began.

Watch out: do not keep pressing the reset button when an oil fired heater is going off on safety-reset. Doing so risks causing

dangerous PUFFBACKS, OIL BURNER

Random loud oil burner noise - pipes vibrating

(Jan 7, 2015) Ellen Bowser said:
Since replacing our old hot water furnace with a new one we have had a noise problem and had the men back several times.

Randomly, several times a day a very loud noise followed by the pipes vibrating when furnace starts up. Shakes the whole house. Drained the line,s change the flow and replaced flaps to allow a slower flow of water. This is so loud it wakes everyone up with a startle.

Reply:

Ellen

We need to inspect the equipment closely before and at the start of this noise complaint, using if necessary a mechanic's stethoscope if the sound source is not obvious. Noisy burners or chimneys can be quite dangerous; or the noise could be a circulator or even loose piping.

See HEATING SYSTEM BUZZING NOISE and

see OIL LINE BUZZ & VIBRATION CURE when the oil burner noise is traced to or is transmitted by oil lines & pipes

...


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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2023-11-09 by InspectApedia Publisher

@Jim,

On a multi-zone hot water heating system where the zone pipe lengths are significantly different , the installer usually includes a valve right at or near the zone drain. Each loop needs its own control valve. It may be recognizable as a valve that's turned by a screwdriver instead of the typical faucet handle.

Each zone is then adjusted so that when all of them are calling for heat at once they get the right proportion of the hot water circulating. Otherwise you may have a zone that never gets warm and another one that's usually too hot.

On 2023-11-08 by Jim

@InspectApedia Publisher, like the one above we talked about or is the flow balancing valve something different?

On 2023-11-08 by InspectApedia Publisher - flow balancing valve may be needed on that zone

@Jim,

It does sound like possibly the problem is the pump is pushing water faster than it can return

there may be a valve partly closed somewhere or a flow balancing valve is needed on that zone.

On 2023-11-08 by Jim

@InspectApedia Publisher, Thank you. So I feel that what is happening is that the lowest zone is also the shortest run. In cold temps when the boiler has a longer cycle when only that zone is open the pump at that time is oversized for that zone and then causes the noise / humming near the end of the cycle. Is that possible.

That’s why I thought the variable speed pump in that situation would slow down thereby not having the pump act oversized. The tech also mentioned that the gas valve is 3/4 inch then gets reduced to 1/2 inch to enter boiler but I think that would cause problems in other zones too. Thoughts?

On 2023-11-08 by InspectApedia Publisher - installing a differential bypass valve to solve buzzing or vibration noise

@Jim,

About installing a differential bypass valve, yes that can solve a buzzing or vibration noise problem in hydronic heating pipes, BUT in my OPINION, that problem is unusual in residential heating systems since it's caused by excessive pressure or flow in some of the hydronic heat piping. I'd want to have a more reliable diagnosis of your system before we start spending much on adding devices.

We want to understand why on a residential system the problem that this valve solves is really what's occurring. For example if you have a tall building with lots of vertical piping there could indeed be a pressure difference between supply and return.

Below we illustrate a Nibco differential pressure by-pass valve. Here is how Nibco explains the valve:

The Webstone Differential Pressure By-Pass Valve eliminates the noise, inadequate boiler flow, and stress on system components caused by excess pressure in a zoned hydronic system with a fixed-speed primary circulator pump, or other system configurations where flow rates may widely vary. The valve opens in low-demand operating conditions, ensuring proper flow to the boiler and preventing over-pumping of zones.

Under partial loads, the DPBV opens to ensure quiet operation and appropriate pressures at the boiler circulator. With all zones active, the DPBV remains closed. It can be installed between the boiler supply and return lines or between zone legs in larger systems. It’s available in straight or angled body options, can be installed in any orientation, and does not require periodic maintenance.


- Nibco, 1516 Middlebury Street, Elkhart, IN 46516-4740 USA, web: www.nibco[dot]com retrieved 2023/11/08, original source: nibco [dot] com/brands/webstone/system-efficiency/DPBV/

On 2023-11-08 by Jim

@InspectApedia Publisher, ok so no air in the system for sure. System runs great when two or three zones run. Also when top two zones run individually no problem. Only when lower zone runs by itself and must be very cold outside.

If lower zone runs by itself and its above 30 then also ok. Never a problem with the old boiler. What do you suggest as a next step? Ty

On 2023-11-07 by InspectApedia Publisher

@Jim,

If a variable speed pump that you can try a different speed settings is making a difference and indeed the noise is from water velocity or combination of water velocity and perhaps air in the system.

I would prefer to have some more diagnosis before throwing money at the problem.

On 2023-11-07 by Jim

@InspectApedia Publisher, He was just guessing. Anyway I read a thread where it mentioned if you have one zone that buzzes and closing the gas valve off a little silences it then you may need a differential pressure bypass valve installed.

It further goes on to mention that a variable speed pump would make the valve unnecessary. I have a taco 007 fixed speed pump and was going to swap it for a variable speed pump like the vr1816 taco. Does this make any sense??

On 2023-11-07 by InspectApedia Publisher

@Jim,

Closing the gas valve down on your gas fired heating boiler would be expected to reduce the flame size and thus the rate at which the boiler is heated, giving a longer on-cycle; I'm not sure what it does to boiler efficiency. And I'm going to have to think and research to imagine why that fixed the humming noise in heating pipes.

Usually that's due to water velocity - more suggestions are at https://inspectapedia.com/plumbing/Plumbing-Noise-Type-Checklist.php

or due to noise transmission from a motor or control into the piping by direct contact: pipes then can act as an amplifier as can flooring, framing, etc.

What did your tech say about why he or she closed down the gas valve? Did the tech say the noise was in the gas piping not the heater's hydronic (hot water) piping?

On 2023-11-07 by Jim - All boiler pipes have a vibration

@InspectApedia Publisher, yes thank you. All boiler pipes have a vibration to it. Definitely not a transformer. Only happens when lower zone is open by itself in cold weather ( 30 or below). Tech got rid of it by closing the gas valve off like 70 %. If other zones are open the sound never occurs.

On 2023-11-07 by InspectApedia Publisher

@Jim,

Before we can tackle this and find and fix the root cause of the buzzing noise that you describe we need to understand where the noise is coming from.

I can't tell from your question if the control is buzzing or if the buzzing noise is from vibrating pipes or from a burner or from something else.

Perhaps you could help by narrowing that down for me and then I can comment further.

On 2023-11-07 by Jim

I have a water boiler with three zones. All works well except when it is quite cold outside and only the lowest zone is activated I get a pretty loud humming sound with vibration during the end of the heating cycle.

I was able to replicate this to a HVAC tech and he was able to silence it by significantly closing the inlet gas valve. I feel this is not the true fix. Is a variable speed pump the answer? Please help. Ty.

On 2023-03-19 by InspectApedia Editor - When my boiler stops running there is a buzzing noise

@Diane,

Above on this page you'll see the most likely sources of buzzing noises - please do take a look through those and keep me posted.

On 2023-03-19 by Diane

When my boiler stops running there is a buzzing noise that starts. I’ll shut the power off and and the noise stops. I wait about a minute and switch the power back on. Then the boiler starts up when needed and and stops running again the buzzing noise starts,

On 2022-12-16 by InspectApedia (Editor) - Constant buzzing noise night and day

@Jackie,

There could be a failing control or transformer used on a control board. It's easy to diagnose, when you hear the buzzing try turning something off.

On 2022-12-16 by Jackie

Constant buzzing noise night and day, if I shut off all electric at the power source it still buzzes, can it be my thermostat or furnace which is forced air electric.

On 2021-12-21 by Inspectapedia Com Moderator - track down the humming buzzing sound to its source

@sue k blan,

We need to track down the humming buzzing sound precisely to its source. Try, with care not to get shocked near live electrical contacts, to use a mechanic's stethoscope to identify with certainty exactly what component is the source of the sound.

Above on this page

AND in more detail at

RELAY CONTROL SWITCHES - causes of chattering humming or buzzing relay controls

we list all of the known reasons that a heating system control relay might buzz or hum. In essence we have either a defect in the relay itself (it's having trouble opening (turning off) or closing (turning on), or there is a defect in the surrounding components such as a switch or electrical connection that is attempting to operate the relay.

An example of the second problem might be a failure at any control component in the heating system, like a zone valve end-switch that is failing or even simply a loose thermostat wire connection that is allowing arcing or vibrating.

On 2021-12-21 by sue k blan

I just had the honeywell relay box RA832A switched out and replaced with a resideo RA832A because there was an awful HUM/BUZZ coming from the relay box when it was performing (I have 3 zones in my home, and the other 2 relay boxes DO NOT hum when performing). The change to the new resideo did not cure the hum/buzz.
What can I do?

On 2021-10-28 by Inspectapedia Com Moderator - fan whining noise vs buzzing at a motor

@Steve in Palm Springs ,

I would like to but can't explain your fan's whining noise from our remote spot up north where we can't see a thing about your installation.

But in general a buzzing or whining electric motor that won't start, if it's a new problem and nothing else was changed, could be a failing fan motor or fan control relay. A service tech might try a hard start capacitor for the fan motor as an inexpensive, diagnostic quick (if not long-lasting) fix.

On 2021-10-28 by Steve in Palm Springs

I just read your answers for a Fan that will not turn on by thermostat command which you state the following:

Step 2: I would continue diagnosis by watching the behavior of the fan limit switch as the furnace heats up; presuming nobody has messed with the switch to try to change its settings, it should act as described in the article above beginning at FAN LIMIT SWITCH TROUBLESHOOTING

This article series answers most questions about central heating and air conditioning system troubleshooting, inspection, diagnosis, and repairs. We describe how to inspect, troubleshoot and repair heating and air conditioning systems to inform home owners, buyers, and home inspectors of common heating system defects.

However here is my problem- I had a newer 5 ton unit installed about 10 years ago from orig 40 years ago and when the heater would turn on very cold air came out of our ducts for a few minutes ...

So we complained to the mgf. Who sent out their tech people from factory in az. They adjusted some timing device that would not turn fan on immediately however this did not do the job very well so we stopped using the furnace at night & went with electric blanket.

Now the fan turns on but its delayed by about 2 minutes...In other words we hear the electric device trying to start the fan with a whining sound however the fan does not engage for about 2 minutes? Can you explain?

On 2021-09-25 by inspectapedia.com.moderator (mod) - Buzzing noise at blower fan, fan will not turn on

@EB,

I'm certainly glad you caught this problem soon and before there was a fire which can sometimes happen when I filter is drawn into the blower fan assembly.

Check the blower motor to see if there's a reset button and if there is not I suspect that the motor jammed and has been damaged and will need replacement.

On 2021-09-25 by EB

Wife heard a buzzing sound. Found air filter sucked into squirrel cage. Fan will not turn on. Replaced motor, but was not a motor issue. Heat or AC will turn on, but no blower. Ordered a new starter capacitor (could not test w/ meter but spinning the squirrel cage with a screwdriver while calling for air/heat didn’t work). Any ideas? Will spinning cage always work as a test for bad starter capacitor?

 

On 2021-02-26 - by (mod) - heating system buzzing noise sources

@Bob Frable,

As you may see in the article above there are quite a few common sources of heating system buzzing noises - you'll want to step through those to see if that helps you with your own system buzz.

Often paying close attention to the furnace (forced warm air heat) system or using a mechanic's stethoscope can find the actual noise source, tracing it to a motor, for example.

Your observation that the buzzing is intermittent makes it harder to find the cause,

Your observation that the buzzing occurs just briefly at start-up is a clue that's worth some thought:
a burner problem or a mechanical source that dissipates when the flame is stabilized or when the equipment is warm (bad bearing)

If you feel unsafe I absolutely agree with keeping your distance, but you should also be prepared to shut the system off immediately if you see what looks like a heating system safety issue.

On 2021-02-26 by Bob Frable

Our furnace, about every third time it comes on, at most 30 seconds after it starts, starts vibrating and rattling for about 5 seconds, then calms down. The rattling reminds me of a fan, so I'm guessing that's where the problem might be.

I haven't stood close to it when this happens, 'cause I fear what could happen afterwards. My brother and a specialist he knows have been solving other problems with it recently, one of which was an old, clogged nozzle, which was replaced.

On 2021-02-14 - by (mod) -

Or more likely a slight pressure or temperature changed in the fuel system

On 2021-02-14 by PJ

Well, the buzzing sound has stopped now. I ran the furnace for about an hour before the sound went away. Could it have been dust/dirt from changing the filters that disrupted the flames (and perhaps gas flow)? Would that have caused the valve to buzz?

On 2021-02-13 - by (mod) - safe to run a propane furnace that has a buzzing gas valve?

PJ

I want to be helpful, and I'll tell you what I can, but just consider how dangerous and impossible it is for someone sitting in Northern Minnesota on the edge of freezing Lake Superior, and who wants you to have heat and be warm too, to possibly know if your heating system is safe!

Sometimes we hear a little buzzing at a gas valve that's traced to fuel flow and is not an urgent repair item; often a little buzzing is caused by vibration of the diaphragm that, in essence responds to pressure to regulate the outflow from a gas pressure regulator or control.

If that's all that's going on, a check for a loose control valve at the propane tank (or slightly opening or closing that control) can stoop the vibrating regulator and thus the buzzing noise; or a small adjustment of gas flow or flame at the gas burner can fix the buzzing noise by very slightly changing the rate of flow of LP gas through the regulator.

(We do a similar thing when we slightly open or close the main water control valve to stop water pipe whistling noise).

BUT if the noise you're hearing is accompanied by an LP gas leak, or if a propane furnace gas valve has failed in a way that its control is not regulating gas pressure or regulating the on-off status of the burner properly, that's very dangerous.

Watch out: So to be safe you'll want to ask for help from your gas supplier or your heating service technician.

On 2021-02-13 by PJ

Is it safe to run a propane furnace that has a buzzing that may be from the gas value? There is no smell of gas.

On 2021-01-27 - by (mod) -

Honor

I can't say why a water pump would be attached to a home heating system (I call hot water heat - baseboards, radiators, etc - a boiler and I call forced warm air heat a furnace - just so we're on the same page).

But if a motor is making a terrible noise it's almost certainly in trouble, probably failing. You'll want to call your heating service tech. and be alert meanwhile to shutting down the system if it appears to be catching fire or smoking.

On 2021-01-26 by Honor

What does it mean if what seems to be a water pump attached to my furnace is vibrating very loudly? Sounds almost like a drill.

On 2020-12-05 - by (mod) -

Carmen

From your text I can't say what's happening in your gas fueled furnace;

An on-site heating service technician would try to isolate the sound source. Some of these, such as a bit of vibration from a motor that is transmitted through piping or other materials, may be normal while others, not.

If you're sure it's a new sound and particularly if it increases you should call for heating service and ask for a safety inspection.

On 2020-12-05 by Carmen Largent

since I had our 500 gal propane tank filled, the furnace now makes a humming sound when the burners light. The appear normal in color, PERHAPS a little higher. The humming sound stops after the fan comes on. What is causing this? Is it dangerous?

On 2020-11-25 - by (mod) -

Buzzing noises can come from several sources Mike so we need to take a closer look. Examples of heater buzzing sources are given above; that's a good place to start.

Let me know what you see or hear.

On 2020-11-25 by Mike Kearney

Buzzing and vibration from new furnace

On 2020-11-06 - by (mod) -

Deb

Humming could be a nearby low voltage Transformer or it may be that you have a piece of equipment that's not functioning. I'm sorry but I can't tell from just the text that you posted

On 2020-11-03 by Deb

Low water shutoff box on my oil hot water furnace is humming, also air in baseboard heat and pipes when heat goes on , problem?

On 2020-03-02 - by (mod) -

I want to help, Bertha but don't understand enough of what equipment is installed. It sounds as if you have a gas fired steam boiler (furnaces are hot air heating systems) - but I don't know what the compressor is doing.

Ask your church heating service company to take a look at the equipment; there could be a safety or simply a reliability concern. :Let me know what you're told and we can comment further.

On 2020-03-02 by Bertha MURPHY

our church has a gas -steam furnace that has a compressor sitting 3 feet away that is vibrating the wall and making a loud noise this an unsafe problem

On 2020-02-22 - by (mod) -

Sharon

It would be helpful if you could use the "add image" button to post a photo of the controls in question, then I can comment further.

But yes, a transformer can vibrate or hum.

Details are at LOW VOLTAGE TRANSFORMER TEST

On 2020-02-22 by Sharon

I have a hot air Dettson oil furnace with a Newmac wood furnace add on. Sometimes when using the word furnace And the thermostat in the living room is activating the draft blower fan there is a loud vibrating or humming noise.

Our tech replaced the relay and we didn’t hear the noise for a while. Now the noise is back. The noise seems to be coming from a box on the left side of the relay. Would that be the transformer ? And why would it buzz or hum.

On 2018-04-04 - by (mod) -

I'd have asked the sound engineer to identify the sound transmission path: perhaps a buried plumbing supply or drain line passing under or near your buildings?

I might also ask the neighbor to double check that the vibration or noise from their heater is normal and not an indicator of a malfunction or unsafe condition.

On 2018-04-04 by Sue

A neighbor across the alley from me built a garage that is heated with a coiled heated concrete Floor.

The heat is coming from a small boiler on the back wall of the garage. I've lived in my house 22 years and ever since they started using the garage my house, 30 feet away hums/ vibrates.

I have had an engineer do vibrational sound reading and it is there in my home. I feel that it is the heat in the Floor of their garage because it goes away in the summer. Is there anything that you can help me with because they will let me go in the garage With someone to figure it out.

On 2017-11-26 - by (mod) -

Jack,

Perhaps the new circuit board is Troy Moore low voltage current than the previous one. But rather than go back to the old board I would consider replacing the Transformer.

On 2017-11-17 by Jack

So here is my situation - I recently replaced the control board on my Goodman GMP075-3 furnace with WR 50T35-743. With the old board in place I never heard any kind of sound when the unit was powered on but not running (off cycle; thermostat not calling for heat).

Now with the new board in place, it seems like the transformer is buzzing (even though the unit is not running).

If I turn off the power supply, it goes silent. Should this happen? If I put back the old board, the buzz stops. Can someone help me address this?

On 2016-11-30 by Dan

I've just had 2 zone valves (Sunvic) fitted to separately control under-floor hearing in one room and the central heating in the rest of the house.

When the valves open or close there is a loud noisy buzz for 45 seconds or so. Is there such a thing as a silent (or at least very quiet) actuator? The noise is driving myself and Mrs Dan mad... Thanks

Moderator reply: buzzes traced to heating baseboard lines, zone valves, baseboard covers

Dan that sounds as if the zone motor or relay is failing and needs repair or replacement. I'd do that soon, before you lose heat on that zone.

If you just touch the water pipe (don't burn fingers) does the noise stop?

An alternative explanation is vibration transmitted through water piping or even water noise in the piping itself.

I've also traced buzzing in hot water heating baseboard to a combination of vibration caused by movement of heating water through the piping (too distant to blame directly on vibrations at the boiler or circulator pump) and on to cause vibration in the baseboard covers.

Just touching the baseboard cover stopped the buzz.

Question: Buzzing sounds from heating controls

When my oil burner is starting up I hear a loud buzzing from the boiler room.

Reply: check for a bad relay or a relay that is being impeded by the control cover

Buzzing noisy aquastats, also any other heating controls that use relays, such as some cad cells, stack relays, and circulator relays: if you hear a buzzing sound coming from your aquastat check to see if the control cover is pressing down on one of its relays. Details, photographs, and an explanation are

at HEATING SYSTEM NOISE DIAGNOSIS.

Also check for a bad relay in the control. Often a failing relay unit will buzz in a heating system control.

On 2014-03-02 by Matt - humming buzzing circulator pump

My circulator pump (Taco 007) started humming or buzzing a few days ago.

But hot water is definitely getting circulated to baseboards. So it appears to be working

Besides the buzz the only thing unusual is that is seems some baseboards are taking longer then usual to fully heat. But I can't really verify that. I may just be imagining that.

On 2014-02-20 by (mod) -

Gary that sounds correct. When heat is running the boiler will shut off when its internal temperature reaches the HI limit.
The circulator will continue to run until the call for heat is satisfied at the room thermostat.

When heat is not already running, when the room thermostat calls for heat the thermostat turns on the circulator to send hot water to the heating zone baseboards or radiators; as returning cool water drops boiler temperature the boiler's burner will then turn on.

On 2016-03-12 by (mod) - buzzing oil burner stopped working

Sounds like a problem with the oil line, perhaps clogging, or at the filter (clogging) or in the fuel unit on the oil burner.

Just guessing as of course by mere e-text we're missing more clues. It's time to call for repair. let me know what your service tech says.

On 2016-03-12 by Judith

I do not know where to begin, my oil burner stopped ( summer winter type) so no heat or hot water.
I hit the reset fire but not starting.

I called the for help.Yes oil in tank almost full.yes it was serviced in late summer.

A vibrating buzzing sound It was replaced then all h broke loose

. I am up to a tiger loop. Between all of this the pipes are banging clanging just before the burner stops all together and at start up system .

I must also back up the system will work for a week then shut down with the noise. I can prime and burner will start and stay on for a week at a time. So let's say it has been going on for about a month.

Do I need a new burner? will the Tiger loop work? or what is the matter(Cause) of the havoc.

Question: oil burner won't run, it buzzes

(Feb 5, 2013) Brian said:

My oil furnace cuts off several times a day. As it goes to cut back on, the thermostat will click, and there is a buzzing sound at the furnace.

After a few seconds of buzzing, the red button will trip. After I push the red button to reset, it will buzz again, but a light to moderate bump to the top of the igniter will cause the furnace to kick on. I've already replaced the igniter.

Any idea what could be the issue? Thanks

Reply:

When the oil burner trips off on safety reset DO NOT keep pushing the reset button.

Once is OK. More than once floods the combustion chamber and makes actual service and repair more costly, difficult, and dangerous.

Your heating system needs service and repair by a trained service technician. Some typical reasons for oil burner failure are in the article above.

We discuss buzzing electrical relays at HVAC NOISE group 1 - banging, bearings,

BUZZING RELAYS


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