The thermal switch on a water heater, also known as a Thermal Cut Off Switch (TCO), is a safety device designed to shut off the gas supply if the water heater overheats.
Purpose of the Thermal Switch
The primary function of the thermal switch is to prevent dangerous situations by cutting off the gas supply when the water heater experiences excessively high temperatures within the combustion chamber. This can occur due to several reasons, including:
- Flammable Vapors: Exposure to flammable vapors, such as spilled gasoline.
- Poor Combustion: Inefficient burning caused by a blocked vent.
How the Thermal Switch Works
The Thermal Cut Off Switch (TCO) is a resettable switch. When the water heater's combustion chamber reaches a dangerously high temperature, the TCO trips, interrupting the gas supply to prevent further heating.
Resetting the Thermal Switch
After the cause of the overheating is addressed (e.g., removing flammable vapors, clearing a blocked vent), the thermal switch can typically be reset. However, resetting the switch without fixing the underlying issue will likely result in the switch tripping again. Refer to your water heater's manual for specific instructions on how to reset the TCO.
