Intermittent Furnace Issue
It's an Atwood 8516-III manufactured in 1994. The furnace runs fine with normal noise and air flow but sometimes the fan will run but the thing won't ignite. This is intermittent - may be two weeks...
Forum Discussion
In cases like this, I would start with the sail switch. If I was troubleshooting, I would run wires out of the unit from both sides of the sail switch, and if you get a failure, try connecting the wires and seeing if it works to prove that it is or is not the sail switch. It is a tiny contact that could be pitted after many years of use.
