How to Replace an Electric Water Heater Thermostat



This DIY repair guide explains how to replace the thermostat in an electric water heater. The thermostat turns the heating element on and off to maintain the water temperature. If the thermostat stops working, the element either won't come on at all and the water is cold or the element stays on too long and the water is scalding. Replace a broken thermostat with the manufacturer-approved replacement part.

Follow these steps to replace a thermostat in Kenmore, State, A. O. Smith, Rheem, Whirlpool and Reliance electric water heaters.

Repair difficulty:
Time required:

Less than 30 min.

Part Required

  • Thermostat

For manuals, repair guides, and specific part recommendations, enter your model number.

Tools Required

  • Work gloves
  • Phillip screwdriver
  • Slot screwdriver
  • Needle nose pliers

Before you begin

Wear work gloves to protect your hands.


 Warning: Undertaking repairs or maintenance to appliances or power equipment can be hazardous. Should you choose to undertake repairs or maintenance, you are assuming the risk of injury to your person or property. In an effort to reduce the risk, use the proper tools and safety equipment noted in the applicable guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs or maintenance, however, should only be performed by a qualified technician.

How to Replace the Thermostat on an Electric Water Heater

Step 1: Shut off the electricity

Switch the two house circuit breakers dedicated for the water heater to OFF.

Step 2: Remove the heating element’s access cover

Remove the heating element’s access cover mounting screw and pull off the cover.


Fold the insulation back to expose the thermostat.

Step 3: Remove the plastic shield

Lift up the tab located at the top of the plastic shield to release the shield from the thermostat.


Remove the shield.

Step 4: Remove the thermostat

Loosen the screws securing the wires to the thermostat. Pull the wires out.


To release the thermostat, pull the tabs outward at the top of the thermostat bracket.


Slide the thermostat up and remove it from behind the thermostat bracket.

Step 5: Install the new thermostat

Place the new thermostat in the bracket making sure it fits firmly behind the tabs and against the tank.


Reattach the wires to the new thermostat and tighten firmly.

 Tip: Use the wire diagram located on top of the water heater showing where each wire connects to the thermostat.

Step 6: Reinstall the plastic shield

Reinstall the plastic shield over the thermostat and heating element.


Fold the insulation back over the thermostat and heating element.

Step 7: Reinstall the access cover

Reinstall the heating element cover and screw.

Step 8: Restore power

Flip the house circuit breakers to the ON position.