Wierd sound from Water Heater


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Old 10-26-10, 04:46 PM
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Wierd sound from Water Heater

Hi all:

Lately when my gas water heater is running (heating water), I hear sounds from within. The sound is as if water is boiling or bubbling inside. I don't see any leak outside, it is totally dry. Before I used to hear the sound only when a faucet would open, but now it happens constantly for as long as water is being heated. Once the heater cuts off, the sound stops.

I have it set at Medium. The hot water that comes in the faucet is not too hot, just fine.

Is there something to worry about here? Just ignore it? What could be causing this? Is this a precursor to some failure?

I would appreciate any help.

Thanks.
 
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Old 10-26-10, 05:12 PM
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Sediment drops to the bottom of the tank, forming an insulated cap over water next to the burner on the bottom. That allows water below the cap to boil, which is what you are hearing.


Connect a hose to the drain valve and open the drain valve all the way. Let the water run at maximum velocity, which will help entrain debris and carry it out the drain valve.

Occasionally run the drain water into a bucket. When it runs clear you can shut off the water and your noise should be gone.
 
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Old 10-26-10, 05:35 PM
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Thank you for the response.

I just looked up some videos on youtube. Do you think I should cut off the cold water supply while draining, or I should let it keep coming? Also should I shut down the water heater by turning off the flame so that the water becomes cold before I do it or I can do it while the water is hot if I am careful enough?
 
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Old 10-26-10, 07:02 PM
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Turn gas gas control knob to the "pilot" position so the main burner wont turn on.

And don't drain the tank. You want a maximum water flow out the drain valve to entrain debris that has collected on the bottom of the tank.
 
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Old 10-26-10, 07:39 PM
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Sorry you said "dont drain the tank". Won't letting water drain out of the drain valve "drain the tank"? I am sorry this might sound stupid, but I am confused by your last statement. Am I missing something here?
 
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Old 10-26-10, 08:01 PM
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Leave the water to the tank turned on. Open the drain valve. Water will flow continuously under pressure into then out of the tank at the bottom. The turbulence of the water flow should entrain sediment that's accumulated at the bottom of the tank and carry it out the drain valve.
 
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Old 10-26-10, 08:52 PM
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Gotcha. Thanks for your help.
 
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Old 12-06-10, 03:18 PM
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The problem didn't go away!

So I finally got a chance to do what SeattlePioneer suggested. Here is what I did:

1. Early morning moved the knob to Pilot only thereby turning off the burner.
2. By afternoon the water was cold enough that I could handle.
3. Hooked up a hose to the water heater and took it all the way outside the house.
4. Opened up the drain outlet in the heater.
5. Note the cold water input was still on, and I didn't open up the vent.

I was expecting a very dirty water, but it appeared to be clean. I used a bucket and it would show some deposits but very little. After sometime even that went away, so I figured its time to turn off the drain outlet. Removed the hose, and turned on the burner.

Guess what? The sound started coming up again. Note this happens only when the burner is on. When water is hot and the burner is not on, no sound comes, neither by itself nor from opening a faucet. But when the burner is on, turning on any faucet in the house causes a roar like sound to come from the attic up stairs where the heater is. If I am standing next to the heater when that happens, I can hear bubbles like sounds.

I was very hopeful this process would fix the problem, but unfortunately it didn't. Anyone has any other ideas? Did I not do it right? Did I miss something?

Thanks.
 
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Old 12-07-10, 11:25 AM
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You might want to try draining it completely empty then turn the water on wide open. This might loosen up more of the gunk in the bottom.

I wouldn't worry too much about the gurgling, it's what they do. About all you can do is flush it once or twice a year.
 
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Old 12-07-10, 11:40 AM
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What make, model and yr HWH? If its old enough the sediment may be all thats keeping it together. If over 10 yrs and never been drained before, sometimes they start leaking soon after. This is just my experience. The sound most likely is cavitation.

From waterheater rescue regarding sediment.

Sediment: Why its buildup is bad for water heaters

Mike NJ
 
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Old 12-07-10, 12:03 PM
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Thank you guys for your responses. That sounds like a good idea to drain it completely empty. Can I leave the pivot on while I do that?

My water heater is about 5 years old, so it is not too old. It is also good to know that it doesn't appear to be dangerous or anything. I can just leave it gurgling ... right?
 
 

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