How To Know If Water Heater Thermostat Is Bad

I test if it should or should not be heating and then if it is.

How to know if water heater thermostat is bad. If it isn t then it is a bad thermostat. You will see the electric wiring that handles the water heater. How to test an electric hot water heater thermostat. No light bummer the thermostat is bad.

Locate the screws that hold the electric access panel to the water heater. The reset button is independent of the thermostat setting so if your description is correct it could be a bad thermostat. Begin by turning the breaker inside the breaker panel of water heater off. Next remove the screws and open the panel.

You should see it open at the specified temperature otherwise you know it s bad. Heater i do not measure resistance of the element. Thermostat failure can be caused by contaminated fluid or simply an old thermostat with weakened springs. See replacing an electric water heater thermostat for instructions on what to do.

If the top thermostat checks out you need to check the lower one. You want to use the water heater tester to check terminals 1 and 2 on the upper element this will be the lower set of 1 and 2 terminals. Remove the upper and the lower access panels with a phillips screwdriver. The upper thermostat controls the upper heating element and the lower thermostat controls the lower heating element.

Turn the water heater circuit breaker off inside the main service panel. You should get a glow or light if the contacts are engaging. If you turn the hot water tap and cold water runs out then the upper thermostat is damaged. Coolant leaks around the thermostat housing or under the vehicle another indication may also be leaking coolant which can be caused by the thermostat not allowing coolant to flow when it is stuck.

Heat up a pot of water to the stamped temperature on the thermostat and use a pair of pliers to hold it under. When you check your electric water heater you will notice two thermostats on the unit one at the top and one at the bottom. Each of these devices controls two different heating elements. A bad thermostat electric water heaters have 2 thermostats an upper thermostat and a lower thermostat.