Instructions on how to replace an electric water heater thermostat. Find out how it works, problems associated with the thermostat failure, and how to avoid some issues.
Upper and lower thermostats control upper and lower heating elements. If the electric water heater is not producing any hot water or the temperature is not as requested (set), some testing must be performed to determine which thermostat is bad.
Furthermore, the thermostats will allow one heater to work in a simultaneous mode, so they heat water at the same time or non-simultaneous mode. Water heaters thermostats are surface mounted and are firmly attached to the side of the tank. Any looseness will affect the normal operation.
These are designed to sense the heat through the tank surface and set the temperature. As part of the thermostat is the ECO or high limit switch (if applicable), which protects the unit and users from extremely high temperatures.
The hot water temperature inside the storage tank is factory set at 120 F as a safety precaution, so by using a dial, you can easily change the output temperature. If you increase the temperature setting above the factory pre-set temperature, there will be a danger of scalding injuries, and heating might not be economical. The time needed for scalding burns or serious injury is as: if the temperature is set at 120 F, it takes more than 5 minutes to produce injuries, for 140 F less than 5 seconds and 160 F about half a second.
The procedure of replacing a water heater thermostat applies to either the lower or upper element.
Electric water heaters are usually equipped with two thermostats: lower and upper ones. The upper one has a high limit, which is non-adjustable, and when it trips, it must you must reset it manually. If the hot water inside the heater increases to an extremely high temperature, the high limit switch is triggered, it interrupts the heating, so it requires manual reset.
When selecting the location for the electric water heater, it is crucial to provide adequate clearance between the thermostat and surrounding elements so the thermostat can easily be used for temperature change, replaced if broken, and cleaned as part of regular maintenance.
Words of caution
Do not perform any work on the thermostat or water heater with the power ON. Always make sure that the breaker is in the OFF position. It is recommended to contact a professional for the proper thermostat replacement.
As said before, this guide is for homeowners who are capable of doing DIY home projects. The guide provides some useful tips that will help you learn how to replace an electric water heater thermostat, identify and solve problems that can affect the proper heating.