Water Heater Thermocouple Troubleshooting & Repair Guide

Water Heater ThermocoupleHow Do I Change My Water Heater Thermocouple is a question many people ask when their water heater pilot light goes out. On older gas water heaters changing the thermocouple was a fairly simple job that involved getting the new thermocouple unscrewing it from the gas valve, pulling it out of the holder on the pilot light assembly and putting the new one back in place.

On newer water heaters changing the water heater thermocouple has become a lot more complicated. There is no longer just a generic thermocouple being used in all of the water heaters. Many of todays water heaters use special thermocouples called thermopiles which generate a higher voltage that can be used to power electronic controls or, thermocouples that incorporate a one time thermal fuse, which can shut the gas flow off when a FVIR (Flammable Vapor Ignition Resistant) event occurs.

The newer water heaters that have the FVIR technology are a lot more difficult to change the thermocouple because they have a sealed combustion chamber that has the combustion air flowing through a flame arrestor. There is no longer an easy to open access panel to reach into and just change the thermocouple. Instead a sealed door is in place and the burner assembly is connected to this door. You will need to consult the manual for your water heater for instructions on how to open this sealed combustion chamber to replace the thermocouple, select the proper thermocouple or, thermopile, and how to reseal the combustion chamber door.