Thermocouple Replacement, Putting it back together
After the assembly is cleaned, place the orifice back in and reattach the gas tube to the assembly.
Ensure the connection is tight!
Thermocouples come in a variety of lengths but it is alright to replace one with a one of a longer
length. Get a good universal type which comes with the adapters you could need for mounting it.
Place the thermocouple back in the mounting bracket and reinstall the bracket.
Next, you can reconnect the gas tube and thermocouple to the gas valve. Ensure that the gas connection
is tight. Then you should turn the gas back on to the furnace.
Follow the instructions on the furnace/water heater for lighting the pilot. If there are no readable
instructions, here is a general guide.
Turn the gas valve knob to pilot, then push it down. You may have to hold it down for a few seconds to
get the air out of the pilot gas line. Use a long match and light the gas at the pilot outlet. Wait
several seconds and release the valve knob.
Now, you should check the pilot gas connections for a leak and tighten as necessary. You can use a
heavy soap solution or a commercially available gas leak detector. You should spray or brush the
solution on the connections and watch for very tiny air bubbles to form.
Also, you should verify that the pilot flame is touching the end of the thermocouple. The flame should
be blue and steady.
ENSURE ALL GAS CONNECTIONS ARE LEAK FREE!
Now, you can turn the gas valve knob to on. Turn the electricity back on to the furnace and run the
unit through a normal heating cycle. Complete your thermocouple replacement by verifying proper system