Heating System Noise FAQs

Q&A on Diagnose, & Repair Heating System Noises

Animal Noises Related to Heating System FAQs

Tip: See HOWLING NOISES in BUILDINGS

Water heater sound of large animal snorting

It’s my furnace or water heater.

The noise reminds me of a large animal pushing air out of its nostrils or air being relieved from a bleeder valve on the bottom of an air compressor.

Last time I heard this noise was Dec 25, 2017. Any idea what could be going on? On 2018-01-28 by Nick -

Dog barks at the furnace because of strange furnace clanking noise

Our dog keeps barking at the furnace because of a strange sound it is making, and we are looking to get the problem solved.

It is good to know that a clanking in the heating system pipes may be heard as a normal consequence of expansion of metals during the heating cycle.

Learning that this noise can be eliminated by careful routing of piping is helpful information. We will look more into this with our HVAC contractor, thanks. On 2017-07-11 1 by Jade Brunet:

High Pitched Whining noise coming from all my walls when the heat goes on

I have a high pitched whining noise coming from all my walls when the heat goes on. The sound is even present in the hall. My downstairs neighbor also has the sound I live in a two story garden apartment and this noise started three years ago when the management installed a new boiler.

the maintnenace people cant seems to figure it out and its only getting worse. Any idea what this could be? J2015/10/27 Jody

Reply:

Usually the noise situation you describe is traced to electric motor vibration, a circulator pump vibration, or noises that originate at the boiler but that are transmitted into the building via the heating pipes. Sometimes simple sound isolation such as using sound isolation on pipe supports or on oil burner fuel piping will fix the complaint.

Because there could also be unsafe conditions right at the boiler, a professional inspection of the system is warranted.

Banging Booming Hammering Heating System Noise FAQs

Tip: See BANGING HEATING SYSTEM NOISES - home

If the noise is associated with forced warm air heating ducts see BANGING NOISE at AIR HANDLERS or in DUCT SYSTEMS

Watch out: if the boom or bang noise is coming from oil fired heating equipment be sure to read the warnings at OIL BURNER SOOT & PUFFBACKS 

Booming noise from heating system ductwork

My ductwork for heat pump system booms every few hours. Outside temps have been single digits at night. Ductwork may never have been cleaned. Rectangular metal. Not insulated. On 2018-02-05 by Carolyn

by (mod) - heat pump system booms every few hours

Sounds like thermal expansion and contraction of the metal ductwork.

Sometimes, too, I encouter booming noises when large sections of metal ductwork are exposed to air pressure changes such as a powerful blower fan coming on or off.

First review BANGING NOISE at AIR HANDLERS or in DUCT SYSTEMS

Then if you need to identify other banging booming noise sources (finding it wasn't the ductwork) take a look at our diagnosis suggestions at

• BANGING HEATING SYSTEM NOISES - home
• BANGING BOOMING NOISE DIAGNOSIS & CURE - home - sources of bangs booms in buildings
• DUCT & AIR FLOW PROBLEMS 
• HVAC NOISE-1 BANG BUZZ VIBRATE - banging, bearings, buzzing, thumping

Forced hot water heating system makes loud banging noises

My heating system is a FHW system and it makes loud banging noises. I have a new relay and pump already installed. Still making loud banking noises On 2017-10-11 by Tom

Reply by (mod) - forced hot water heat banging noise from pipes or radiators?

Tim,

Be sure to review the details of diagnostic suggestions for banging noises found at

BANGING HEATING PIPES RADIATORS 

Hammering noise at old boiler

I have an older boiler system heating a 4-plex.

When I shut the manual valves off to the front /rear hall rads( not necessary for heat there yet) I get a hammering noise in the boiler room.

I notice that when the boiler shuts down, the temp gauge keeps rising well beyond the boiler thermostat setting.

When I run the system with the front/rear hall radiator valves open, everything runs fine. What gives? Thanks On 2017-09-18 by Terry -

Reply by (mod)

First, where is the noise coming from: pipes and radiators? If so,

see BANGING HEATING PIPES RADIATORS 

Next: if the hammering noise occurs when you're closing a water flow control valve anywhere on the system,

see WATER HAMMER NOISE DIAGNOSE & CURE 

Banging noise at new gas boiler

We have a new gas boiler that has been installed. One zone makes a loud banging noise when the zone comes on or turns off.

We did not have this problem with the old boiler. What can we do to fix the problem? - On 2017-02-25 by Deirdre Lintott -

by (mod) - safety first! then check for a zone valve closing + water hammer noise

Deirdre

FIRST let's confirm where the noise is occurring. If it is at the boiler itself then the system may be unsafe, particularly if the noise is a gas explosion. IN that case I would TURN OFF the boiler and call for emergency repair.

If the banging noise is coming from other mechanical components like a zone valve or circulator pump, the problem is probably mechanical and still needs repair but is less likely to be an emergency.

So, next: if the noise is NOT occurring when the boiler flame ignites, and if the hammering noise occurs when you're closing a water flow control valve anywhere on the system, such as a heating zone valve, then

see WATER HAMMER NOISE DIAGNOSE & CURE 

Also search InspectApedia.com for BANGING HEATING PIPES RADIATORS to see more banging noise diagnosis and repair advice for heating boilers

Also see BANGING BOOMING NOISE DIAGNOSIS & CURE - home

Water hammer banging noises in heat piping

We are having our unfinished basement finished which included moving some water pipes about 12 inches over on the ceiling of the basement.

Ever since we are hearing many water hammers and banging noises both when hot water is running and not running.

The plumber has insisted that all he did was move the pipes and it is nothing he has done. Any ideas? (Dec 26, 2014) Robin

Reply:

Robin it would be odd for adding finish materials to directly impact plumbing though I suppose it might re-direct sounds a bit. I'd take a look at our water-hammer diagnosis and repair advice at

WATER HAMMER NOISE DIAGNOSE & CURE 

Loud THUMP noise from heating system every 20 minutes

I live in a condo building with hot water heat. At night, at twenty-minute intervals, I hear a loud noise. It sounds as though the upstairs fell out of bed. It only happens during cold weather.

The building manager assures me these noises are normal, however I am the only person who is hearing the noises. It is a loud thump, followed by little thumps. On 2017-05-01 by Carolyn -

Reply by (mod)

Carolyn, the noise may be normal if it's metal ductwork expanding, contracting, or moving in a forced air heating or cooling system.

Such noises can also be caused by an air handler turning on or off causing metal movement in the air handler itself or in ductwork.

But if the noise occurs when a gas or oil burner turns on, that is dangerous.

Watch out: if that's the case, have your building mangaer read the warnings at OIL BURNER SOOT & PUFFBACKS 

Loud popping sound when A/C comes on

I have a miniboiler model emb-9 that is making a kind of crackling noise when heat is called for then stops and seems to work and heat properly On 2015-11-19 1 by Tom Neely

Banging Drum sound from water heater I replaced our water heater and I still have a sound like a drum a various hours of the day.

On 2016-01-28 by Stan Kato -

by (mod) - Snap, Crackle, Pop, Banging Drum & similar HVAC noises

Tom: Look for thermal expansion of metal parts - if so that's probably harmless.

Other sounds, if related to flame or to overheating could raise safety concerns.

Stan: I suspect there is a scale problem in your water heater - explained in detail

at BANGING WATER HEATER

Loud bang from expanding metal in propane fireplace - chimney damage?

I have a propane fireplace about an hour after turning it off there is a very loud bang. The dealer states this is the metal contracting. My question is will this cause any damage to the chimney? 25 January 2015 Sandi

Reply:

Sandi:

OPINION: I would indeed ask for a careful inspection by a certified chimney sweep or fireplace installer (not your dealer), and I would also give a call to the manufacturer of your fireplace heater - or give us the brand and model of your heater and we'll also research this question.

Watch out: While some metal expansion noises may be normal, I'm concerned that flexing of metal components might ultimately cause cracking that could create a fire or carbon monoxide hazard.

Banging boiler noises after it was modified

My boiler was modified (shortened) to build another room in the basement.

Ever since that happened, it makes a banging noise when the blower goes into the shut down cycle. Does anyone know what that is? (Mar 24, 2015) Anonymous

Reply:

Anon

Watch out: for safety, be sure to see first our explanation and warnings at

PUFFBACKS, OIL BURNER

Then, ask what has changed?

Where is the banging : ductwork, pipes, or at the boiler itself. The latter could be dangerous.

please searcvh InspectApedia for these diagnostic articles

BANGING HEATING PIPES RADIATORS
BOILER NOISE SMOKE ODORS

Buzzing Heating System Noise FAQs

Tip: See these articles on diagnosing buzzing noises at heating systems or components:

• HEATING SYSTEM BUZZING NOISE - originating at the equipment itself. Review this article first if you hear buzzing from any heating system component.
• BUZZING SOUNDS - sounds from A/C, heat pump or inverter or from other equipment
• OIL LINE BUZZ & VIBRATION CURE - originating at or transmitted by the heating oil piping
• BUZZING NOISE DIAGNOSIS - home - other sources of buzzing sounds in or around buildings

And since some buzzing sounds may also be described as a humming noise, also see

• HEATING SYSTEM HUMMING NOISE SOURCES
  

Locate the buzzing noise from electric heat vent

I hear a buzzing sound coming from my vent in the upstairs hall way. I have electrical heating and air condition. How do I locate the problem. (Jan 9, 2015) Anonymous

Reply:

Watch out: if the buzzing noise is coming from an electrical connection there is risk of a building fire. You say you have electric heat. If you have a buzzing electric heat baseboard, for safety turn it off at the electrical panel immediately and then call a licensed electrician for help.

If we assume the noise is related to the operation of equipment, try turning off individual appliances or circuits one by one to narrow down the source.

I'm not sure if you are hearing a relay buzz, a control buzz, a fan motor buzz, or loose ductwork rattling.

Buzzing noise coming from box over heating pipe going to one of our heating zones

We have 3 heating zones. One of them we turn the thermostat up and takes awhile just to bring up the temp a degree or two even though I raise it 6 to 8 degrees.

Theres also a box (basement) over the main heating pipe that goes to that zone.

Theres a buzzing sound coming from the box...does anyone know what the problem is? On 2019-01-10 by Pjh

by (mod) - buzzing noises in unidentified type of heating systems - hot water?

Pjh

From your brief note I suspect there is a failing relay or motor in a zone valve.

But you don't indicate for sure what kind of heat you have: hot water, forced warm air, or something else.

If my guess is right that you have hot water heat and the "box" is a zone valve or circulator relay, then see the diagnosis and repair advice at

CIRCULATOR PUMP NOISE REPAIR - noisy zone circulator could be a bad zone valve, or a bad circulator relay.

Other buzzing circulator relay noises are dicussed

at CIRCULATOR PUMP RELAY FAQs 

And see CIRCULATOR NOISES for a complete catalog of heating zone circulator noises & their common causes.

At HEATING SYSTEM NOISE DIAGNOSIS - home - you will find descriptions of and links to details about the various sources of buzzing noises at heating systems.

Heat pump buzzing heat pump sound heard through vents

I have a heat pump system that usually is not running due to alternative heat source I use.

However we get a buzzing sound continuously in the attic from the air handler system .

Any idea what may be causing this relatively loud buzzing sound that can be heard through the vents? On 2017-04-23 by Armand

by (mod) -

Armand:

Take a look at the sources of buzzing noises in an HVAC system listed in the article above.

Then go take a closer look at the air handler, checking for

- a failing low voltage transformer

- a failing control relay switch

- a loose blower door or motor mount or other component

More details you might review for help are

at BUZZING SOUNDS - sounds from A/C, heat pump or inverter or from other equipment

Let me know what you find.

Dan

Old Gas fired Wall Heater Buzzing non-stop

There is a gas wall heater in the bathroom. It has not been used since 1965.

Yesterday it began making a buzzing sound and has no stopped. There is no odor of gas. Is this a dangerous problem? What could be causing this?

by (mod) - buzzing gas wall heater

Mary

From just your e-text I can't know what's going on nor what is causing the buzzing - it could be an electrical component such as a relay, switch or transformer, or it could be bees.

Watch out: for safety I suggest that you

turn off the gas supply to the heater

turn off electrical power to the heater or if there is no separate electrical switch, ask your electrician to disconnect it and to safely cap off its wires.

A bath heater that has not been used for 50 years is surely not needed.

A guess is that there is an electrical control or relay needed to start the heater and that is not working.

For more detailed troubleshooting see HEATING SYSTEM BUZZING NOISE

Heater Chirping Noise FAQs

Tip: See HVAC NOISE-2 CHATTER CHIRP CLANK FAN GROAN 

or go directly to

• CHIRPS or CHIRPING SOUNDS at the AIR HANDLER - air conditioner , furnace, or A/C control
• CHIRPING CRICKET NOISE at the COMPRESSOR/CONDENSER
• CO ALARM CAUSES - includes explanation of chirping CO detectors and/or smoke detectors (low battery)

What's the Source of Chirping noises in my new house

Maybe you can diagnose a sound for me? I am in a new house, about 3 yrs old. Ever since our move-in I've noticed a sharp chirp which occurs at a fairly consistent time interval, maybe 2-3 minutes apart. It sounds very much like a smoke detector that needs a new battery.

I've wandered around our unfinished basement trying to pinpoint the sourse and it appears to come from the furnace, an electric model (can't remember brand right now).

I want to put an extra bedroom in the basement but this chirping would drive me crazy if I had to sleep there. It seems to be coming from higher up on the unit, somewhere north of where the ducting comes from the top of the unit but I can't be sure.

This isn't a chirping like a bird, ie multiple rapid chirps.

This is just one sharp, loud chirp which repeats every couple minutes like clockwork

Any suggestions? I appreciate your help! (July 16, 2012) Bill said:

Reply: check your smoke or CO detectors for low battery chirping sound

Bill, you might want to go back to our root noise diagnosis article beginning at

Search InspectApedia for - NOISE / SOUND DIAGNOSIS & CURE

Chirping as you describe is often traded to a smoke detector that was stuck somewhere not obvious.

We explain this at CO ALARM CAUSES

Look also for a CO detector that someone may have just plugged into a wall receptacle somewhere.

HVAC Equipment Clicking or Crackling Noise FAQs

Tip: See HEATING SYSTEM NOISE DIAGNOSIS - home

Also see CLICKING NOISES

and POPPING SNAPPING NOISE DIAGNOSIS

Crackling Sparking noises at the heater

I keep hearing spark noises at my heater. (Apr 3, 2013) kev

Reply:

Kev take a look at the diagnosis and repair advice at

GAS IGNITER DIAGNOSIS & REPAIR

Watch out: if your gas appliance is not igniting and working normally it may be unsafe; in that case shut it off and call your heating service company for inspection and repair.

If your "heater" refers to a water heater then also see the diagnostic and repair advice

at WATER HEATER NOISE DIAGNOSIS, CURE - a notorious source of loud clicks and pops

Heating baseboard noises, ticking clicking noises from heat piping

The thermal baseboard heater is making a lot of noise in my apartment, and I don not wich is the problem (Feb 4, 2014) Anonymou

A loud ticking noise is coming from my ceiling in my living room when ever heater is running.

There is a bedroom above my living room and it looks like it is coming from heating pipes running across the ceiling, need advice what needs to be done to fix the problem. Thanks. (Mar 2, 2014) Mumtaz

Reply:

Often these TICKING NOISES are thermal expansion of piping or building materials.

In that case we can fix the problem by using noise-resistant plastic or nylon pipe supports or by cutting clearance openings around the pipe at passages through building materials.

You may need to seal such openings with a fire-resistant foam.

Heating Equipment / Water Heater Hiss Noise FAQs

Tip: See HISSING SOUNDS in BUILDINGS

Boiler / Water Heater Hisses

My hot water tank/boiler/immersion heater is hissing even when everything is off. Any ideas of what this may be? Thanks - On 2017-01-08 by Sg

by (mod) - hissing at the heating boiler

Sg,

I'm sure there may be other causes of hissing at the heating boiler besides that which occurred to me immediately.

But the first thing I would look for would be a leak in the boiler itself. For example a leak into the combustion chamber.

We explain these concerns and repairs

at HISSING WATER HEATER

Sometimes also a leak in piping or controls above the boiler may drip water onto a hot surface.

So I'm suggesting we start by looking for water leaks.

This may be difficult for you to do unless you have some training.

But your heating service contractor can certainly inspect the inside of the combustion chamber and should be able to show you if there is an indication of leakage there.

See all of our water heater noise troubleshooting procedures

at WATER HEATER NOISE

Heating Equipment Humming Noise FAQs

Tip: See HUMMING NOISES in BUILDINGS

There's a Humming noise all over my house

I have a low frequency hum/vibration noise that I can feel/hear in every room in house, it goes on and off for hours, I have shut off the water from stop tap and noise is still there.

I have also switched the electricity off from the mains and the noise is still there. Do you have any advice?

Thanks Ann. On 2017-04-01 b

by (mod) - low frequency hum/vibration noise

If you turn off all of the mechanical systems including plumbing and electrical and heating in the noise continues, but at least we believe that the noise was coming from it exterior source.

At that point I'd be looking for a nearby low voltage transformer or for a piece of equipment that uses an electric motor that is having trouble starting.

Popping Noise from HVAC Equipment FAQs

Tip: See POPPING SNAPPING NOISE DIAGNOSIS 

Loud Popping Sound from the Thermostat When the A/C comes on

Our brand new home with American Standard thermostat control display unit make a loud "popping" sound when activated for the a/c.

Slightly less when it goes off. We've had the contractor/builder, electrician and HVAC guy out and they say there isn't anything to do. "All these low voltage thermostats make this noise." This is the first time in a slew of homes we have owned that this is an issue.

Is this an issue? Should we be concerned? Should we have an independent HVAC company out to review the system prior to our one year warranty with the builder expires. Any help would be grateful..... Thanks, July 11, 2012) vanessa

Reply:

Vanessa, I suggest noting the brand and model of your thermostat and then giving the manufacturer a call. Or send us a photo of the thermostat along with its brand and model number and we'll research it further. Most thermostats in homes use low voltage wiring at which electricall-generated noises would be unusual.

If your thermostat is a 120V model, an unsafe electrical short or electrical arcing could be the problem.

But for this question and with no more information we can't second guess your onsite people, but loud popping from a thermostat sounds unusual to me and I imagine that the manufacturer would like to know about it and would have some advice for you.

Keep us posted on what you're told - what you learn will help other readers.

Roaring Noise from Heating System FAQs

Train sounds when furnace shuts off

Train like sound when furnance shuts off...usually when the downstairs shuts off first (Nov 19, 2014) Kathleen

Reply:

Kathleen,

Watch out: Since a train like sound can indicate a chimney fire I would turn off the system and call your heating service company for emergency service.

If the noise continues AFTER you turn off power to your heater you should leave the home and call the fire department.

Hopefully the issue is something else.

In that second, perhaps less urgent case, you still need a heating service tech on site.

(Roaring?) airplane noise from heating ducts

Our ducted heating system sounds like we are sitting in plane. I dont' know what to do. We built this new home 3 years back.

Heating installed at that time. Any advice pls. On 2016-05-20 by Mandy -

Reply by (mod) - first rule out a chimney fire, then look into air movement or leaks

In ductwork air movement or air leaks often make a roaring or hissing sound. See LEAKY DUCT CONNECTIONS and also see VIBRATION DAMPENERS for a discussion of devices used to isolate noises produced by HVAC air handlers.

Watch out: A chimney fire sounds like a roaring freight train.

If you suspect a chimney fire and can do so safely, shut down your wood stove (close all air intakes) or close any chimney dampers as well, immediately exit the building, and call the fire department from outdoors.

We explain that concern in detail

at CHIMNEY NOISE DIAGNOSIS

Tracking Down an Unidentified Noise FAQs

Unidentified noise from outdoor furnace: Raytherm Raypack 133 furnace

I have a noise coming from my furnace which is located outside. I have a raytherm (raypak) 133 furnace which also heats up my domestic water.

My circulator pump runs 24/7 and I recently just replaced it, so I know it can't be that.

The noise I hear is a quick 2 second noise that happens right before the furnace turns on. I'm not sure if it can possibly be some type of valve that might be broken inside and that's rattling or perhaps something else?

Can someone please help me. I will try to make a video and post it on youtube. I will post the link once I get that done. (Mar 5, 2014) Anonymous

Reply: isolate the noise to a specific component, part, or at least to a building location

Anon we'll be glad to look at your video, even copy it at InspectApedia to invite further comment if that's helpful.

A first step might be to try to isolate the noise to a specific component. One can do this by careful observation at equipment start-up or by employing a mechanic's stethoscope or even a simple short length of pipe to check and listen to different device.

Another approach is to ask what device operate at the start of a heating cycle. Examples include:

- an automatic barometric damper or flue damper that operates before the burner comes on
- a quickstop valve on the oil line
- relays that are turning on a hot water circulator

- a draft inducer fan

To track a mystery-noise or sound to its source in a building, try keeping a noise log, noting the conditions, times, events, and information we list in our sound event log worksheet:

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

Keep us posted and we'll pursue it.

Wailing Sounds from Heating Equipment, FAQs

Tip: see the complete noise cause and cure index at WATER HEATER NOISE - topic home

Wailing Sounds from a Noritz Tankless Water Heater

Sporadic Short Wailing sounds from a less than 6 month old Noris tankless water heater - On 2018-04-10 by Lana

Reply by (mod) - here are sources of tankless water heater noises including and similar to wailing

Lana, I've found odd noises at tankless water heaters, particularly ones fired by LP or natural gas where the vent or chimney size, routing, openings, or venting could be adjusted to get complete silence. But there are some other things to check.

Take a look at our diagnosis and repair advice at

WATER HEATER NOISE - topic home - includes an alphabetical index to all water heater noises or sounds and their cause and cure, including

• SCREECHING WATER HEATER
• SCREAMING WATER HEATER
• SHRIEKING WATER HEATER
• TANKLESS WATER HEATER WHISTLE  - shrieking, whining, wailing water heater sounds from a Bosch MiniMAXX tankless water heater

Whining Sounds from Heating Equipment, FAQs

Tip: To track down a whining noise at heating equipment see

• HVAC NOISE-5 SCREAM SING TRUMPET WHINE WUWU - scream, sing, squeal, trumpet, water sounds, whine, whoosh, whistle, wuwuwu, or silence
• WHINING - A/C compressor/condenser or blower fan motor noise

Also see the complete noise cause and cure index at WATER HEATER NOISE - topic home

How do I stop the whining noise on water heater FASCO draft inducer

Eliminating the loud whining noise on a (FASCO 239-45584-00) water heater exhaust draft inducer. On 2018-03-11 by John

Reply by (mod) -

John

Whining noises at a draft inducer might be from the draft inducer fan or from air movement. We need to look more carefully at the system to see if it's an air movement noise, a mechanical noise, or a bad or failing electric motor or bearing noise.

But most often we trace whining noises in mechanical systems to bearings in electric motors or other mechanical devices (whining, grinding, vibrating, maybe humming).

Best would be to have an onsite expert familiar with the Fasco draft inducer. Where I've met that noise problem I found

- missing or improperly-installed draft hood

- a need to adjust air intake around a draft hood

- improperly sized, routed, or partly-blocked flues or flue-vent connectors