Hot answers tagged water-heater
It turns out it's nothing to do with the water heater. The sump pump's backup battery, which is pretty close to the water heater, exploded inside its container. That's what caused the smell.
I would definitely have the two circuit separated. In fact, they should have been from the start. If the water heater is a "standard" 4500 watt tank-type then a 20A breaker is not adequate anyway. You'd need #10 wire with a 30A two-pole breaker.
By shutting off the water main, there is no way for expanded hot water to be relieved by backing into the main. This causes over-pressure and either the pressure relief valve is letting some water out (hopefully into the pan) or the high pressure water is opening a flaw in the tank or a through-hole, such as a heating element, spigot, or water connection. ...
A water expansion tank gives water a place to expand in a closed system (frequently found with boilers, or home water supplies with a check valve). Otherwise, heated water cannot expand and instead increases pressure until some component of the system leaks or explodes. If the tank is on the hot water heating system, then it's there to relieve expansion ...
Only top voted, non community-wiki answers of a minimum length are eligible