David, The problems could be a few things..and over the years I have had all of these problems and figured them all out. The bigest problem was the
Battery. It takes alot of power to run furnace fan and then turn on gas valve. I found on my
Boler it takes no less then 12.9 V, with nothing on, to start with, to run furnace all night
Propane...is it turned on and is it getting to gas valve in heater/
Should be checked by competant person if your not comfortable.
Does
Battery have enough power to turn on GAS VALVE? did you try the heater while hooked up to shore power.
Gas valve is no good....
If standing pilot is pilot a good flame and in right area, and is thermo-couple working?
Electronics....may need a Dinosour mother board to replace yours