This is the same process you use to replace the thermocouple on your hot water heater. Expect to pay a minimal cost for the thermocouple; you'll save a lot of money by replacing it yourself.

TOOLS AND MATERIALS REQUIRED MATERIALS Epoxy glue, contact cement, TP valves, thermocouples, electric water heaters, gas water heaters, water heater dip tube, replacement water heater element ...

These power the ceramic heating element, as well as provide the soldering iron handle access to the thermocouple that’s placed near the actual tip. With a simple diagram [Clive] explains how ...