Duo therm furnace question

[crunchie]

Having recently sold my truck camper, it has a duo-therm forced air furnace. I've used the furnace for two moose hunting seasons flawlessly. When I went to show the buyer how the system works, I couldn't get the thermostat to allow the main gas valve to open even though the pilot light was lit and the gas valve was set to on.
But I also didn't have a 12 volt battery hooked up, was using 110 vac at the the time. When I was moose hunting, I always had a battery hooked up.
My camper does have a 110vac/12vdc converter for the lights, water pump, the fan on the furnace, etc.
My question is, does anyone know if it's a must to have 12 volts present when running the furnace? Maybe the thermostat isn't hooked up to the converter?
thanks anyone.
crunchie

[crunchie]

i don't own have the camper anymore but if the new owner can't figure it out I'll be back.

[enblethen]

What is model of the furnace? That makes a difference.

[crunchie]

Thanks a lot.

[Mandalay_Parr]

Some converters work best with a battery connected. Yes, furnace does require 12volts.
Might try installing a battery, then test furnace.