Noise from inside water heater

gyrfalcon

When we run the water, hot or cold,  from any fixture and then stop the flow, there is a noise that happens from inside the hot water heater, it almost sounds like a noise from inside a submarine as it goes deeper, like metal creaking with changing pressures.  Has anyone heard this type of noise from a water heater before?  It’s not a kettling noise from from what I can tell. 

hot_rod

What is your water pressure in the home? Does the relief valve on the tank  ever drip?

excessive pressure can make noise as will sediment in the tank when the burner is running

gyrfalcon

Pressure is 60lbs.  Expansion tank 60lbs.  

Sound does not happen when firing , just when water flow stops. Relief valve does not drip

Larry Weingarten

Hi, @hot_rod nailed the common causes of noise in a tank. Is there any way you can record the sound and post it here? With that, we can probably narrow it down.
Yours, Larry

neilc

do you have a PRV on the domestic?
I have one at work that howls once in a while

gyrfalcon

https://jmp.sh/s/Ck88tIpRZjNani2DvOoA
Lets see if this audio link works

gyrfalcon

Anybody??  

I tried using a mechanics stethoscope on the water tank jacket and Expansion tank seems loudest at the jacket. I also shut off the cold inlet to the tank and the noise was not present then. 

Larry Weingarten

Hi, I just get a 404 note saying the audio file is not available. So, noise has something to do with pressure. Does it happen only when flow stops? Have you put a pressure gauge on the tank drain and then run water to see what the gauge tells you? If you see large pressure differences, it could be a pressure reducer on your main line that is failing.

Yours, Larry

gyrfalcon

I’m trying to get the sound recording file to load but I think the format is not compatible.  I’ll try again later 

gyrfalcon

Yes. Noise only happens when flow stops. 

I’ll check pressures tonight 

gyrfalcon

trying again.

hot_rod

I’m thinking maybe you are hearing the PRV react to the shut off of flow. A pressure gauge would confirm the PRV is not over pressurizing

gyrfalcon

I attached a pressure gauge to my water heater drain. Initial reading was 70 psi.  I observed the needle while water was being used in the  kitchen and bathroom. Pressure would sometimes go to 50lbs and then around 60. Finally resting at 70lbs again. 

hot_rod

70 psi is fairly high  pressure. PRVs are typically factory set to 45 or 50 psi

but that pressure  shouldn’t be causing a water heater tank to flex

EdTheHeaterMan

Do you think the Ty-D-Bowl man might have gotten lost in the piping on his way to clean your toilets?



That could be his motor boat making all that racket

gyrfalcon

@EdTheHeaterMan, I appreciate your humor, but no Ty-dee bowl boats in my house. 

I left the gauge on the tank last night and checked it this morning. Almost 80 psi. And it’s holding there while someone is in the shower.  If I recall the water pressure and domestic expansion tank are set at 60 lbs. 

i just disconnected the gauge and then reconnected and now reads 55.  

psb75

Not sure whether it is sound from pressure differential or possibly sound of heat expansion of materials as hot water flows out of the tank?

Larry Weingarten

Hi, Maybe I'm making it up, but in the recording I thought I heard water running and then as soon at it was shut off, the creaking started. As a test you could dial down the PRV to 50 psi and change the charge in the expansion tank as well. If you get adequate flow at the reduced pressure, it certainly will put less stress on the tank. I'd watch pressure and see if it creeps up over time. If so, that's a sign of a failed PRV.

I normally get that creaking noise at higher pressures though. Are you pretty confident in the gauge you're using?

Yours, Larry

Big Ed_4

It is the Death Rattle , Mineral build up with the sound of energy breaking through .

gyrfalcon

The tank is a Richmond 50 gal. LP atmospheric. Approximately 4 -5 yrs old . 

I have adjusted the pressures- water and expansion tank (system drained off and isolated)
to about 55 psi.  Gauge seems accurate . I could try another  I suppose. 

Noise still present just  as water flow stops.  

This is limestone county so lots of calcium in the water. Maybe there is some mineral  build up.  

Thanks for everybody’s input.  Y’all are grrreat!