Thumping/Banging noise from Hot Water tank.

**Iknownothing** · 02-03-2011, 06:11 PM

Hello, Just replaced the elements in my HW tank and two days later there is this sort of thumping/banging noise coming from the top of the tank. I'm not sure how to describe it really. Hot water works great and the temp was 150, too hot so I brought it down to 125 degrees. Does anyone know what it could be?

**Iknownothing** · 02-07-2011, 08:41 AM

Bump

, No one?

**Dana** · 02-07-2011, 11:05 AM

Did you let the poltergeist out of the tank yet? ;-)

Does this happen randomly, or only when heating up?

Or only when hot water is being drawn?

Or is it correlated with something/anything else?

Does the temperature/pressure valve spit when the noise is happening?

**LLigetfa** · 02-07-2011, 07:57 PM

My gas WH has an anti-percolation valve that makes a clunking noise at the start and stop of water flow or with sudden pressure changes. Did it since day 1. Also, my water is aerated with a micronizer for iron removal and the heat releases some of the entrained air resulting in some air being trapped at the top of the pipe run which makes noises until there is enough flow to purge it out.