Originally Posted by Alberta Mac
We had the pilot light lit and going by itself but funace did not kick in.
We also looked at the wiring for the thermostat on the wall, green wires, but did not see green wires going to the furnace.
The furnace needs 12V to run.
The switch on the right side must be ON and the red knob turned to ON.
The setting on the thermostat must be higher than ambient (you can connect both wires at the thermostat to simulate a warmer setting. On my trailer they are yellow).
The pilot must be lit.
When all those 4 conditions are met, the main burner valve will open, and the the pilot will lit the main burner.
When the temperature inside the casing is warm enough, the fan will kick in.
When the ambiant temp reaches the thermostat setting, the main valve will close and the main burner will shut off. When the heat exchanger has cooled enough, the fan will stop.
If you need to work on this heater, it is designed to be serviced easily by pulling out the internals (a couple screws to remove) and the outer casing remains in the cabinet. I discovered this only after I pulled the whole thing out, which is not necessary.