Water Heater Thermostat Replacement, A Step By Step Guide
The water heater thermostat is the device that turns the source of heat on and off to produce and maintain the home's supply of hot water. The device consists of a bimetal switch that opens and closes based on the expansion and contraction of the metal. The device can be adjusted to maintain the desired hot water temperature. It is a simple matter of turning the pointer on the unit with a small standard screwdriver until it is on the desired water temperature.
When the temperature of the water in the storage tank is below the thermostat's setpoint, the switch is closed. This supplies electrical power to the element.
As current flows through the element, heat is produced and transferred to the water in the tank.
When the water temperature reaches the setpoint, the bimetal in the switch deforms and opens the electrical contacts. This interrupts power to the element and stops current flow and the production of heat.
**NOTE** ONLY YOU CAN ASSESS YOUR ABILITY TO PERFORM THE FOLLOWING TASKS. THIS IS A GUIDE AND CANNOT PROVIDE ALL OF THE DETAILS FOR EVERY SITUATION.
The typical home's water heater will have two thermostats and they are referred to as the upper and lower thermostats. They are not identical. The upper unit typically has three wire connections while the lower unit only has two.
Smaller units such as for apartments will only have one thermostat.