My 12 volt works but...

[Terry78]

My 12 volt side is working. But I still need to work
On the gas system. This trailer has a forced air
furnace with a thermostat on the wall. I am wondering if I can turn it on to test it without
Propane? Will it even try to come on with no gas?
The trailer is a 1979 Terry.

[Old-Biscuit]

Furnace is 12V DC and propane
When t-stat closes the fan will come on to purge combustion chamber then circuit bd will attempt to light off gas via spark electrode
(fan comes up to speed...closes sail switch which allows DC to go to High temp limit switch then to circuit bd)


No propane and circuit bd will shutdown attempts to light off...prevent raw fuel from accumulating


Post brand/model for specific info...DC circuit path