Have HVAC Questions? Ask an HVAC Expert for Answers
Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can
continue our conversation.
Did the plumber replace the lower themostat?
If the heater is turning off via the overtemp reset button then he probably didn't replace the lower thermostat. If you get it going again by hitting that reset (on the upper thermostat) then one of the 2 thermostats is malfunctioning. It's pretty common for the plumber to assume only the upper stat is bad if the reset keeps tripping but the lower can make the water too hot just like the upper.
If you get it going by hitting the reset then it's a thermostat problem. Is that how you get it to work? Anything else would be much more difficult to correct. There's a slight chance you have a bad breaker but that would tend to be a more permanent failure.
Just push the reset. Do not turn off the breaker. If the reset is tripped it will click when you push it. If it doesn't click it either wasn't tripped or the new thermostat is faulty. Be careful to not touch any wires but the newer units have plastic gaurds to cover the wiring so touching the wires isn't likely.
You're welcome. I'd have an electrican check out the breaker and the wiring before buying a new unit. For the price of a minimum call (should only take him 1/2 or less) you can be sure the wiring or the breaker is not the problem.