My furnace won't run unless I go down and lift door and put it back on again. After doing this it will lite and run for one cycle and that is it, I have had it cleaned, and was told it was fixed, but still doing the same thing. I think it has something to do with the door switch. Any help please. It's getting cold. I can also reset my thermostat and it still won't start.

Try replacing the door switch or adjusting it if possible. I feel you are on the right track.