A Thermostat is a device that is used to control the temperature of the water inside the tank of the water heater. There are many different types used in the different water heaters depending on the type of water heater and the type of energy source used but they all control the heating either electrically or, mechanically. The Thermostat usually also has some form of ECO or, Energy Cut Off which shuts off the energy to the water heater should uncontrolled heating of the water occur.
The Thermostat on electric water heaters typically consists of an upper and lower Thermostat located under access panels on the side of the water heater. These Thermostats in most cases are mechanical switches mounted with direct contact to the tank that sense the temperature of the tank opening and closing the switches as needed to maintain the water temperature.
The Thermostat on gas water heaters typically consists of a thermostat built into the back of the gas valve that extends out the back of the gas valve and extends either directly into the water heater tank or, into a thermowell. The Thermostat measures the temperature of the water in the tank and mechanically activates the gas valve to open and close the supply of the gas to the main burner of the water heater thus controlling the temperature of the water in the tank.
Another type of Thermostat is appearing on an increasing number of water heaters that uses thermistors to provide the temperature measurements which is then sent to an electronic circuit board to determine the temperature of the water and control the heating by the output from the board. This type of control is appearing on an increasing number of electric, gas, and heatpump water heaters. In many cases these boards are bringing in â€œSmart Functionsâ€ to water heaters including greater energy savings and troubleshooting options.