Thermocouple as used in RV Appliances
The thermocouple is an electo-mechanical safety device
that senses if the pilot flame in an RV appliance is present. If the pilot
flame goes out, the thermocouple will automatically shut off the flow of gas
through the gas valve, thereby removing the fuel source and preventing the
accumulation of explosive gas mixtures.
When the thermocouple is heated by the pilot flame, a small
electrical current is generated. This micro current powers an electromagnet in
the main appliance valve which holds open the valve that supplies the propane
to the appliance.
If the pilot flame goes out, the electrical current is
interrupted, the electromagnet is de-energized, and the valve closes
When lighting the pilot flame, allow the thermocouple to heat
up for 30 seconds or so before releasing the valve button. If the pilot refuses
to stay lit after several attempts, try gently cleaning the contacts where the
thermocouple screws into the main valve body. When re-tightening this contact,
screw it in finger tight, then tighten 1/4 turn with a wrench. If the pilot
still will not stay lit then replace the thermocouple.
If you don't get any pilot flame at all or the flame is too
weak to activate the thermocouple, your pilot orifice may be plugged, or