Before you do this be sure to turn off the line valve on the gas supply. Take a hex nut driver or screwdriver and loosen the objects holding the two thermocouple wires in place.
Again please don t attempt any of this unless you re certain you can do it in a safe manner.
Natural gas fireplace thermocouple replacement. Gas water heaters generally use the same ones as gas fireplaces. Use it to unscrew the connector that holds the thermocouple to the gas valve then unhook the probe from its clip and pull out the entire thermocouple assembly. You can take out the old ones take them to any local hardware store and pick up a generic replacement.
Some models will use hex nuts while others will simply install screws. Hire a gas fireplace expert if you have any doubts. Turn the gas off to your fireplace entirely and make sure to give the thermocouple about half an hour to cool off before trying to handle it.
Remove the other end of old thermocouple sensor at its mount at the burner or pilot flame. Typically there is a clip that holds the thermocouple to the pilot flame tube. Pull down gently to pull the thermocouple s end out of the mounting well on the gas valve.
The wrench size is typically 7 16. Procedure for replacing a thermocouple the only tool you need to replace a thermocouple is a wrench. 750mv thermocouple for heat glo heatilator fireplace thermopile replacement fireplace stove accessories for fire gas stoves heat glo gas stoves oven water heater frying furnace 24 aluminum 4 4 out of 5 stars 234.