Good afternoon all,
I have a problem with my Day & Night Central Heating Unit. Last night it just would not kick on the heat. No matter how high I turned the thermostat up, it still would not kick on. I removed the front panel and the pilot is still lit. It maybe the thermostat, I'm not sure. Sleeping in a cold house sucks, so any advise anyone can offer will be greatly appreciated.

Thanks,
Frost Bit Bob

How old? What's the efficiency? How many wires go to the gas valve? Is there a printed circuit board in the furnace?

It's like a '69-'70 model. It's a single pole, two wires (one red, one white). There is not a printed circuit board. I changed the thermostat but nothing happened.

Is the pilot lit, or is it self lighting?