My 8 year old electric water heater started to make a strange rattling noise a couple of weeks ago. The noise happens at random and lasts for only a few minutes. Short bursts of noise about a minute apart and stops after about 6 rattling bursts. The noise sounds like a loud groan. I heard this sound about 2 weeks ago for the first time and I've only heard it about 4 times since.We have plenty of hot, clean and soft water. My tank is a RHEEM 40 Gallon.
Is my tank failing?
Electrical – Why is the electric water heater making an intermittent groaning noise
electricalheaterplumbingwater
Related Solutions
You probably have sediment buildup in the bottom of the hot water heater. Pockets of water get trapped in the sediment/scale at the bottom of the hot water heater, turn to steam when it heats up, then "explode" causing the noises you are hearing.
You could try draining the water heater to get some of the sediment out, but honestly it's probably too late for that - might want to have a pro come out and take a look at it. It's not likely a critical issue, but it would be best to get that scale cleaned off to prolong the life of the unit.
If it was the pressure relief valve, then you would see water coming out that line. It sounds like a failing pressure regulator valve to me. To check, pickup a simple pressure meter from the local HI store:
If you see this climbing around the same time the surging sound is happening, locate this device which should be shortly after the main shutoff and replace it:
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Best Answer
Groaning, rumbling, or other low-pitched noises from a hot water heater are typical symptoms of excessive sediment buildup in the heater; normally, flushing it via the bottom drain valve is recommended to clean out the sediment buildup. If not cleaned out, eventually the heater's lower element will burn out due to being buried in insulating sediment (calcium carbonate).