How To Know If Your Water Heater Thermostat Is Bad

The upper thermostat controls the upper heating element and the lower thermostat controls the lower heating element.

How to know if your water heater thermostat is bad. By the third bucket if the water from your heater is still coming out rusty then most likely the water heater not the piping is at fault. I test if it should or should not be heating and then if it is. If it isn t then it is a bad thermostat. Wrap the two wires together and turn the.

However they do go bad and testing water heater thermostats is still required. To look for faults you will need to use a screwdriver. If you want to test a thermostat on an electric water heater you will also need to check the heating element. First it allows the upper element to heat the water in the top of the tank.

Unscrew the two appropriate wires from their terminals. The thermostats are less likely to be at fault than the elements. A good test to avoid replacing a functioning water heater is to drain a few five gallon buckets of hot water out of the water heater. You will also need to check the water heater thermostat with digital multimeter tools.

Usually when the upper thermostat goes bad you will have no hot water at all while a bad lower thermostat makes itself known when there is only a small amount of hot water before the tap water goes cold. If the thermostat has a 4 terminal screw opposite the 1 and 2 screws that s the output to the lower thermostat. This is important especially as open and grounded heating elements result in inaccurate tests. A bad thermostat electric water heaters have 2 thermostats an upper thermostat and a lower thermostat.

An electric hot water heater has two thermostats controlling two separate heating elements one in the upper half of the tank one in the lower half. As you loosen the screws grip the wires with your other hand so they don t slip behind the wall. I do not measure resistance of the element. Again the resistance reading should be 0.

The upper thermostat has two functions. Your water heater usually has two elements and two thermostats. 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.