I personally don't know what might be going on with your furnace
, particularly in light
of the case that both your water heater and stove are getting propane and working. However, I went on the Internet and found this information. I'm sure you already know this stuff, but just in case. I found it at a website called "RV Basics."
Pilot Light Won't light or stay lit.
Make sure the thermocouple is positioned properly in the pilot flame.
Another common problem is a bad regulator at the propane tank. A simple test will indicate if this is the case. Light all the stove burners and look at the color of the flame. The flames should be blue with little or no yellow color. If the flame does not change color then the regulator is probably working. A bad regulator could also cause problems with your hot water heater.
Note: Most modern RV furnaces have a direct spark ignition system that replaces a pilot light.
Fan doesn't run and no heat.
If the fan will not start you should first check that your battery
is good and you have 12 volts at the furnace
. You could have a tripped circuit breaker or blown fuse.
If the battery
is good and you have electricity to the RV's heater next check the thermostat.
Remove cover and look for the "anticipator" adjustment. (Note: Some new thermostats do not have an anticipator.) It will be an adjustable control with a sliding contact over a straight bare wire or a bare wire wound about an insulating material. If the fan will not start set the temperature to maximum and then move the anticipator slider while listening for the fan to start. Be sure to wait long enough... it normally takes our furnace 30 seconds for the fan to start once the thermostat sends a signal.
If the fan starts after you move the slider then you have probably found the problem. In this case you may find a slider position near the original position that will work reliably. If your thermostat anticipator adjustment uses the straight wire design and the wire lies directly on the plastic housing then you should look to see if the wire has sunk into the plastic. This wire produces heat and causes the plastic to melt a little and the wire to sink into the plastic so the slider no longer makes contact. It may be necessary to replace the thermostat.
Fan runs but no heat.
If your furnace fan starts you can assume that the thermostat is working.
Possible problems are insufficient air flow through the furnace a bad propane valve at the furnace or a bad regulator at the propane tank.
A furnace contains an internal sail switch, that senses the air flow. If the air flow is not sufficient then the switch will prevent the furnace from igniting and the fan will run but you will get no heat. A slow motor speed could be caused by a low battery
or other low voltage cause such as a bad connection in the wiring.
Low air flow could also be caused by a restriction in the ventilation system. Check to see if any heat registers are closed or blocked. Some furnaces will not tolerate even a partial closure of a heat register. .
If you have an electronic ignition check to see if the two contacts are touching or are too far apart. They should be about 1/8 apart.