Water Heater Lower Thermostat Problems

Sometimes the dial is accidentally tweaked too high so this troubleshooting solution to fix your water heater is the first step in diagnosing a water heater overheating problem.

Water heater lower thermostat problems.

Turn off the power to the water heater in the service panel. Electric water heater. The thermostats are less likely to be at fault than the elements. Electric water heaters have one or two elements and each is controlled by a thermostat.

Sometimes the element overheats and the water absorbs this heat. On most residential models there will be both an upper and lower thermostat and they should be adjusted to the same temperature. When the upper element works and the lower one does not you have a low supply of hot water. When this happens heat builds up in the upper portion of the storage tank which will eventually trip the reset button.

Check the heat setting on both. Test the wires to confirm the power is off using a non contact voltage tester. You can test them with the power off using an ohmmeter to measure resistance or with the power on using a voltmeter to measure voltage. Your water heater usually has two elements and two thermostats.

However they do go bad and testing water heater thermostats is still required. When the elements get coated or when the lower element is buried under mineral sediment it has to work harder to heat the water. If the hot water heater is not working one of the thermostats may be bad. The lower thermostat just controls the lower element.