Water Heater Lower Thermostat Problems

Electric water heater.

Water heater lower thermostat problems.

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. One common thermostat problem with electric water heaters occurs when the lower thermostat becomes stuck in the on position and doesn t cycle the lower element off properly. Electric water heaters have one or two elements and each is controlled by a thermostat.

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. Test the wires to confirm the power is off using a non contact voltage tester. Check the heat setting on both. When the elements get coated or when the lower element is buried under mineral sediment it has to work harder to heat the water.

The lower thermostat just controls the lower element. On most residential models there will be both an upper and lower thermostat and they should be adjusted to the same temperature. 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. If the hot water heater is not working one of the thermostats may be bad.

Turn off the power to the water heater in the service panel. To test which of the thermostats might be defective allow the water heater to sit for about half an hour after running a generous amount of hot water. Remove the access panel insulation and plastic safety guard from each heating element on the water heater. The thermostats are less likely to be at fault than the elements.