8G50NVH water tank used White Rodgers 927 Thermostat lost function

The White-Rodgers-37E73A-918-Intelli-Vent-Control on my water tank had been changed two times in the past 6-7 years, and it is not control the temperature again. The hot water becomes too much hot than usually， is this normal ? or what's the problem? Can do any repair on it?

Thanks
Adam

 

It's hard to say why this is happening. It is normal for temperature to fluctuate within about a 5-7 degC band, is it possible that this is what is happening? Perhaps consider installing a thermostatic mixing valve on the hot water outlet. It has its own thermostat dial & will automatically mix cold water in with the hot to keep a consistent temperature in your hot water pipes. This way it doesn't matter so much if the tank temperature fluctuates.

 

Check the ground wire in the breaker panel and might add a surge protector for that circuit.

 

Thanks.
Seems the thermostatic mixing valve can mix cold and hot water instead of control the temperature inside the hot water tank? what I worry is what bad thing can happen if the temperature inside too high.
Also, is that possible to DIY a control board by Arduino to replaced the Rodgers 927?

 

Thanks.
I'll do it.