Thank you Randy, it seems like not possible to DIY. The heater looks very clean and new from the outside despite of its age, of course not able to see the inside. It always worked very well and never had any problem over the years until my circuit breaker overloaded. I don’t know much about water heater but just curios to know it stopped working is just a coincidence that it happened the same time my circuit breaker overloaded? Or the circuit breaker overloaded did trigger the problem of the water heater? Thank you.