Originally Posted by DBWOE Art parz
My furnace will come on for a short time then shut off never gets my rig up to temperature that it is set for, the furnace comes on only when I move the thermostat back and forth. I have propane so it's not that. Do I need a new thermostat? I'm in AZ but will be going to Idaho in may will probably need my furnace more there.
You need to define "come on".
Is it just the fan blowing?
Does it produce any heat?
Your furnace is not unique to your Windsport/Hurricane - most RVs use the same brand and similar model furnace.
Search is your friend. There have been numerous posts/threads lately about furnace problems.
Sequence of events for an operating furnace.
The thermostat is always supplied 12 VDC from the furnace - This 12 VDC is used to control both the heat and the A/C.
When the thermostat calls for heat it sends a 12 VDC signal back to the furnace control board telling it to start up.
The furnace starts the fan.
The sail switch is pushed by the fan moving air to tell the controller the fan is operating.
The controller then opens the gas valve and starts sparking the ignitor to light the flame.
Once the flame is lite, it heats the ignitor arm feeding voltage back to the controller (it has a built-in thermocouple) telling the controller the flame is lit.
If this process fails - the controller closes the gas valve and attempts to try lighting again. If it fails to light after 3 attempts the controller has to be reset either by removing power, or removing the call for heat from the thermostat either by turning off the heat function or moving the "Set" temperature below the current temperature.
While running, the furnace may get too hot and turn off the flame periodically to cool down and then relight it to continue providing heat.
Once the "Set" temperature is reached at the thermostat the controller will close the gas valve to extinguish the flame and the fan will continue to run until the furnace is cool enough to shut the fan off.
The controller board has been mounted behind the furnace door. and some furnace doors have been constructed, so that the controller board can get wet in a hard rain. This is is common source of furnace failure.
The controller boards themselves are prone to failure - most people replace them with Dinosaur brand boards when that occurs.
The ignitor itself may fail; either by not igniting or by not sensing the flame.
The mixing tube (where the gas and air mix to burn) and the ignitor may be home to insect nests that cause furnace failure.
The solenoid operated gas valve may fail.
Air may be in the gas lines preventing ignition at the furnace - make sure your stove lights and burns properly.
Your gas valve may be off at the tank.