July 01, 2015

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.

Quick links

Video

Instructions

Tools required

Work gloves

Phillip screwdriver

Slot screwdriver

Needle nose pliers

Repair difficulty

Time required

30 minutes or less

How to replace an electric water heater thermostat repair guide video.

How to replace a water heater theromstat video.

Instructions

01.
Shut off the electricity
Switch the two house circuit breakers dedicated for the water heater to OFF.
Wear work gloves to protect your hands.
PHOTO: Switch the water heater circuit breakers off.
02.
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.
PHOTO: Remove the cover screw.
PHOTO: Remove the cover.
PHOTO: Fold the insulation up.
03.
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.
PHOTO: Remove the shield.
04.
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.

PHOTO: Disconnet the wires.
PHOTO: Release the thermostat.
PHOTO: Remove the thermostat.
05.
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.
PHOTO: Install the new thermostat.
PHOTO: Attach the thermostat wires.
06.
Reinstall the plastic shield
Reinstall the plastic shield over the thermostat and heating element.
Fold the insulation back over the thermostat and heating element.

PHOTO: Reinstall the thermostat shield.
07.
Reinstall the access cover
Reinstall the heating element cover and screw.
PHOTO: Reinstall the heating element cover.
PHOTO: Reinstall the screw.
08.
Restore power
Flip the house circuit breakers to the ON position.
PHOTO: Flip the circuit breakers to the On position.

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.