Review on 🔥 Resideo Gas Furnace, Boiler, and Water Heater Replacement Thermocouple - CQ100A1005/U, 36-Inch by Shawn Hill

I used to think that thermocouples work by transferring heat from a pilot flame through a copper wire to some sort of sensor. So I was worried it would take too long to transfer that heat. It turns out they don't work that way. The heat of the pilot flame causes the tip of the thermocouple to generate a tiny amount of current, which is transmitted through the cable to the control box. So it doesn't matter if you get a thermocouple that is too long. You can easily coil up and tuck away the extra wire so it doesn't get in the way. What you want to avoid is making it too short so it doesn't go from the indicator light to the control box. So order at least the same length as the one you are replacing and you can choose a longer one if that size is not available. BTW, I ordered one to have on hand.