Water Heater Noise Q&A #2
Recent FAQs on water calorifier, cylinder, geyser noises

Water Heater Popping Sound FAQs

Water heater popping noise at start-up

My gas hot water makes a popping noise when starting up. Is this normal ? - (Aug 5, 2016) anita said:

Reply:

Anita

See WATER HEATER SCALE DE-LIMING PROCEDURE to read the probable cause, effects, and remedy for the water heater popping noise you describe.

Water pressure drop everywhere and water heater pops and cracks when we flush a toilet

Recently Have noticed a pressure drop at all fixtures. The real mystery is that the water heater pops and cracks when a nearby toilet is flushed.

The water is hard with a softener and a filter. The heater is two yrs old and has been flushed about every 6 months.

The house is on a crawl space and I have inspected for leaks. Filter has not been changed recently. How can using cold water to flush toilet affect water heater? On 2014-02-15 by Mike Metcalf -

by (mod) -

A water heater should not be affected by a toilet flush unless by mistake we're sending hot water to the toilet; sounds quite odd; I'm baffled but will think about it further.

Hard water does cause water heater noises and shortens heater life - search InspectAPedia for


Water Heater descaling procedures

for more details.

Ringing Noise at Water Heater FAQs

Brrring sound from water heater, intermittent at start-up

A Brrrring sound coming from the hot water heater - only intermittently.

After turning on a hot water tap for a minute, the noise stopped.

The sound seemed similar to a hollow sounding telephone ringing. (Mar 26, 2015) Joanne

Reply:

Thanks for the new sound for our catalog, Joanne.

I can only guess that you are hearing a sound caused by water velocity moving through piping or a valve at or near the water heater, or perhaps even through it's dip tube.

A mechanic's stethoscope can probably pinpoint the noise. Give that a try and let me know what you find.

Be sure to also review our advice

at WATER SUPPLY PIPE WHISTLE NOISE - that can include "ringing" sounds in water pipes.

Question: hear a light ringing sound from the unit

i have a new smith 40 gallon HWH which has been working great until today i hear a light ringing sound from the unit, there are no leaks visually. everything looks great & i have hot water, what could that. be? On 2018-03-11 by lee

Mod reply: Ringing water heater

Ringing water heater is a new one for me, Lee.

What sort of water heater is this : electric, gas, oil, solar?

Where can you pinpoint the ringing noise?

Often high pitched noises in plumbing systems, including at a water heater, are traced to water velocity induced vibration in the piping. Try slightly closing the inlet valve.

Roaring water heater noise FAQ

Roaring sound at water heater after a few minutes

What causes my hot water heater to make a roaring sound after the hot water has been running for a few minutes? (Feb 9, 2016) Jackie

Reply:

Jackie:

Watch out: I don't know what sort of water heater you have - the situation could be very dangerous if a chimney fire is occurring - if you hear noises at the chimney or see unusual smoke coming out of your chimney top then there may be a chimney fire: in that case have everyone leave the home and then call for emergency assistance.

But more likely what you're hearing is a normal "roaring" gas burner flame.

So take a look at the water heater to confirm that the noise seems to come from the gas burner and that you don't see any smoke or flame outside the heater.

Other sounds such as a popping hissing crackling may be due to lime in the water heater tank. Search InspectApedia for WATER HEATER DE SCALE

Rumbling Water Heater Sound FAQs

Water heater rumbling noise like an idling big rig truck

Our 8 mo old gas water heater was making a loud rumbling noise that sounded like an idling large big rig truck, vibrated through the garage and could be heard through the house.

The noise lasted for 30 - 40 seconds and came intermittently many times a day for about 5 days until it stopped and the water heater will now only barely keep the water slightly above cold. This is not a type of noise I saw listed and am confused by it. It sounded as if it was a motor noise and we didn't realize it was the water heater until it died. On 2017-05-04 by Melody -

by (mod)

Melody,

Check out WATER HEATER SCALE DE-LIMING PROCEDURE in the Recommended Articles list near the bottom of this page. Because most likely the sound that you describe is due to scale formation inside of your water heater.

Or you can use the InspectApedia search box on any of our pages to search this website for


WATER HEATER SCALE to see all of our articles on that topic

 

Question: rumbling noise at water heater / geyser

We have a 10 yr old gas water heater. Recently, we installed a new clothes washer. Since then, whenever the washer initially fills (generally only the first cycle), the water heater makes a rumbling sound.

This is definitely related to the start of the water draw, and not to the heating cycle. We drain the heater monthly, and live in an area with cold lime softening and have very little to no scale buildup anywhere. On 2018-02-04 by tslothrop

Mod reply: signs that the calorifier needs to be de-scaled

sounds like a scale problem in your water heater. Search inspectapedia for
water heater descaling

WATER HEATER SCALE DE-LIMING PROCEDURE

Question: rumbling calorifier

I hear water running through the water heater even though I've turned the main water valve to the house off. Is this possible? On 2018-02-02 by Cojo

Reply:

Probably not. But you might be hearing a rumbling sound due to scale in the water heater if your water heater in fact has remained on.

Water Heater Scratching Sound FAQs

Water heater making scratching noises

The HWH in my apartment is making a scratching sound at intermittent times usually from dusk on and continues most of the night. It sounds like a squirrel or rat scratching as confirmed by a pest mgt. company. However when you put your ear up against the HWH you definitely hear the scratching sound coming out of it. I've never heard this before. What can it be? - (June 18, 2014) Bob said:

Reply:

Bob most likely you're hearing the turbulence in a water heater that has mineral scale formation on the heater bottom or heating elements.

Water Heater Tapping Noise FAQs

Electric hot water tank making tapping sounds like a marble being tapped on the tank interior

Have an electric 80 gallon hot water tank that services one side of my house and a 40 gallon that services a guest bathroom on the other side of the house.

We have hard water which can leave hard build up in sinks and showers if not cleaned regularly. Tonight I noticed that my 80 gallon tank is making periodic tapping sounds (much like a marble being tapped on the inside of the tank). I turned the electric off but it is still making those tapping sounds. Husband says not to worry about especially since the electric is off, but it is driving me crazy. What is causing it to suddenly make these noises? - A Harris 11/20/12

Reply:

Indeed Mrs. Harris, a scaled-up water heater may make a tapping sound as hot gases form on the scale-coated tank bottom and as bubbles and water are disturbed in the tank as a result. If that's what's going on it's not always an immediate safety concern, as we've seen scale-coated water heaters remain in use for even a decade without a catastrophe. But ...

Watch out: if the water tank is not descaled the not only will the noises worsen, but it's possible for the tank bottom to be weakened, eventually leading to or contributing to a catastrophic water tank failure, described over at BLEVE EXPLOSIONS.

 

Water heater sounds like spraying a garden hose over an empty trash can.

My water heater is 8+ years old.

The sound its making is like turning on a garden hose and holding it over an empty tin trash can.

It sounds like a stream of falling water also it sounds like boiling water. Do I need to change out the anode tube or a heating element...or something else? We have ready hard water, Im on city water. 2019-06-21 by Joshua Burns -

Reply by (mod) -

What's the fuel? Gas/oil?

I suspect that there's a mineral scale problem. See links in this article series about water heater scale removal.

Other Water Heater Noise Diagnosis Questions

Reader question: Our electric water heater is making a loud noise.

Our electric water heater is making a loud noise. At first, I couldn't locate the noise inside the house until I reached the garage and able to guess that it was from inside the water heater. My husband's home office is located on the other side of the garage wall.

The noise started to diminished but now we are able to expect it to start at 7:33 am lasting 3 minutes on a daily basis. The noise reminded me of when I lived in San Francisco when every Tuesday or Wednesday at noon, a siren would sound off. (that was in the 80s)

We bought this house last August and start finding nuanses here and there. We have an insurance coverage for the first year but the plumbing contacted volunteered to come out to check it however had never encountered this problem.

What or where should I go to find out? How would I check for a response if there is one? On 2018-04-17 by Gardenia

Moderator reply: cure for noisy electric water heater

Gardenia -

As you don't describe the noise my best advice is to check out the common noises and their causes at WATER HEATER NOISE

Examples of common noises:

- water heater hissing: the elements may need to be de-scaled

- water heater banging and popping - the water heater itself needs to be de-scaled or have debris flushed from the tank

Question: pop off valve is making a loud noise

Electric hot water heater put in new pipes new pop off valve, have no leaks but the pop off valve is making a loud noise, release the valve noise stops close valve noise is right back turn on water noise stops turn off water the noise starts again, need help to fix it what do I do. On 2018-03-05 by Lora Woodard

Reply by ACE Heating & Cooling:

@tslothrop,
Sounds like you need a expansion tank installed.

Mod reply: signs that a water heater or geyser expansion tank is needed

Lora

ACE may be spot-on, so thank you ACE.

I would look at the pressure and temperature gauge on the boiler.

If the temperature is over 200F or the pressure close to or over 30PSI than the boiler is overheating and is unsafe.

If the temp and pressure are below that and the relief valve is opening then most-likely the expansion tank is waterlogged and needs to be drained.

It'd be unusual for a boiler to have omitted the expansion tank entirely.

Question: pinging noise in water heater / hot water cylinder

When we start showing the water heater will make a pinging sound. On 2018-01-26 by Johnny

Reply:

if the noise is not coming from the burner it could be a scale problem

Question: why a noise occurs at 4:30 AM?

Our new electric water heater makes a vibrating sound at 4:30 in the morning. It lasts about 10 minutes. The one we replaced did the same thing, at the same time. Got any ideas? The installer was back last week and reduced the water pressure which he thought might be the problem. On 2017-12-16 by John O.

Reply:

What is happening at 4:30 AM? Is there a timer turning the heater on? Is there hot water use?

Reader follow up:

Noise starts at 4:30 am. No timer on the unit. Yes, we have hot water all the time.

Reply:

If the noise is regular in when it occurs then there is likely to be some event that we want to identify. What happens at 4:30AM in your building?

Follow up:

Nothing happens, I am in a single family home. Everyone is sleeping. The noise doesn't happen every morning. Totally random. That's the problem.

Reply: running water noises

When a water or hot water system makes noise as you describe I suspect water is running somewhere, perhaps from a bad toilet fill valve or an automatic water feeder on a boiler, or a water heater is going into a heating cycle.

Question: something is oozing from top of solar water heater

our solar hot water is making a banging noise looks like something is oozing from the top and dripping down cylinder. On 2017-12-02 by susan

Reply: signs of a solar water heater or calorifier leak

Sounds like a leak perhaps caused by water hammer.