electric heater noise

[bigisland]

Aloha,
My water heater makes a rumbling noise everyday and always in the morning and during the day.The water heater is not being heated when the noise happens as I have a timer that goes on at 4.pm and off at 8.pm. The sound travels.The heater is 4 yrs. old and has been doing it for awhile.I drained the heater and the water was clean.

 

[Fansplumbing]

Thermal expansion? Do you have an expansion tank installed. If not, you probably need one.

 

[bigisland]

we have lived here for 25 yrs. and we did not have this problem before?

 

[Fansplumbing]

Sometimes things change without your knowledge. My city is currently in the process of installing new water meters with check valves in the meter. This will create the need for an expansion tank as the water was always able to expand through the meter before. You may want to check and see if your city/county has changed your water meter recently.

 

[bigisland]

now that you mentioned the meters were changed to digtal but don't know if there is a check valve but will check further...thanks

 

[bigisland]

still having noise problem...anymore ideas anyone?

 

[Caduceus]

So your tank is only on for 4 hours per day. Do you use hot water during the morning hours and throughout the day? I'm just asking to see if it is possible that by using hot water while the tank is not on could be causing the problem. Maybe by heating the tank then introducing cold water into the tank every day is causing contraction in the tank body or with a build up of sediment on the bottom of the tank.
Water may come out clear from the drain but you could still have a great deal of sediment and scale in the tank.
Also, it is not recommended to let the water temperature in the tank drop below 120 degrees F. for long periods of time.
Try letting the tank heat normally for a 24 hour cycle and see if the noise goes away. Maybe before that, try a very thorough flush of the tank and check the house's water pressure. Big box stores sell a gauge that easily screws onto a hose valve.

 

[havasu]

My water heater (before going tankless) always made a grumbling noise when the sprinklers came on outside. Being from a rainy climate, I doubt if this would cause a problem for you but thought I'd throw it out anyways.

Gawd, I love Hawaii!

 

[bigisland]

I tried leaving the heater on without setting the timer and still hearing noise.Also checked water pressure and its 98 psi.Anyone got anymore ideas?
Aloha