heaternoisewater
I installed a new electric Rheem model XE40M06ST45U1 water heater last week and for the past four days it has been making a ticking sound. The sound seems to be the loudest near the supply lines. Frankly, it sounds like a grandfather clock!
What could be causing this noise?
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:
I have the same water heater and those knock noises are the flow valve actuators turning on and off...completely normal.
Best Answer
Those ticking noises are likely just the sounds of your "heat traps", one way valves that are used to save energy by not allowing heat from your water to migrate into the pipes, cool off and sink back down to require heating again. Heat traps are often installed as nipples on the cold and hot water lines, so you may not even realize that's what they are. The sound is perfectly normal.
The first image is actually kind of exaggerated, they often look like normal nipples. as in the 2nd image.