Atwood furnace tries to light when thermostat is off

[rustysheros]

The furnace on my 2012 jayflight 32tsbh tries to light/run no matter what setting the thermostat is on. When I turn on the propane the furnace will heat constantly no matter what setting the thermostat is on also. Took off the access panel and seen three blinking lights. From what I've read that usually means the furnace will not light. Not the case here. Anyone else ever have this happen? Any help would be great

[Sunflake]

You may want to check where the T-stat connects to the furnace. I'm not sure what they are labeled on an Atwood. Usually on every residential furnace I've looked at the heat terminal from the T-stat is labeled "W" there should also be an "R" terminal. Somehow you're getting 12 volts back on the W terminal. If you can send me the wiring diagram I'd be happy to look it over and see if I can help.