Bang the side of the heater and it works
A month or so ago my heater stopped working. I went into the basement and inspected, took the panel off and held the button the door pushes closed and lights came on in the panel, but no flame/blower, etc. The light labeled flame would not come on. Called hvac guy who came out and inspected; took the door off and put it back on and it fired up. He said the doors were warped a bit so straightened them by bending. I understood the theory was that they were warped, thus not pushing in the button correctly. I wasn't convinced because it this were the case, then it should work by pushing in the button manually. Hell, he got it working though so I wasn't arguing. It worked fine for a month or so. Recently, failed again. I went down and banged the door on the side (implementing his warped door theory). Wow, it worked. Went back inside and went to bed. Woke up in a cold house. Went down, banged the side, it worked again. I've narrowed it down that the door is a red herring. As long as the button is pushed down and you bang the side of it, the flame and blower fires on, but when it reaches temperature and shuts off naturally, it cannot restart via thermostat data prompting it to fire back up. It may be a loose wire or the like, but I'm worried some safety issue with the flame, etc. preventing it from coming back on. Way over my comfort level to handle by myself, so I would like to call the same guy back and give him new data. Just want to know the possibilities here so I can tell whether he knows what he's doing.
Any comments or suggestions would be greatly appreciated.