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noisy hot water tank
Author: johnale (NY) After each shower my hot water tank makes a banging noise until the tank reaches temp. What would cause this? thank you

Re: noisy hot water tank

Author: SwimRunPlumb (MI)

It's old and has a lot of sediment on the bottom. The heat from the bottom is "peculating" and forming air bubbles trying to escape while the burner is on.

Shut off the gas and water, and open a couple hot faucets in your house and drain it down. When it is empty, give it a couple of blasts of cold water by turning the valve on and off a couple times to stir up the sediment.

Re: noisy hot water tank
Author: hj IT is probably a gas water heater and there are rust "nodules" on the center flue pipe. Water in these nodules turns to "superheated steam" when then blows out into the water in the tank. When that happens the steam condenses to water with an resultant "explosion" which is the sound you hear. Eventually the nodules break open so they cannot trap water and the sound goes away.

Re: noisy hot water tank
Author: RWP (SD) If your water heater is 10 years old or thereabouts give or take a couple of years it is time for a new one as the present one is living on borrowed time. - - - - - - - - - - Retired after 50 years of plumbing and heating.

Re: noisy hot water tank
Author: johnale (NY) Thanks for the help. I will get a new one and keep it on hand.

Re: noisy hot water tank
Author: hj If you keep it too long, its warranty may expire or be greatly reduced. It may never be a factor, but you could be the occassional person who has one go bad in a short time. I had a customer last week whose first heater failed in 2 1/2 years and the replacement lasted just a week short of a year.

Re: noisy hot water tank
Author: johnale (NY) thanks for the tip