Magic Furnace Repair

No end of broken stuff to fix and having a hard time getting it done, though I did fix the furnace today. Turned it on the other day and no hot air. Last time this happened I called the furnace man. He came out and found the air filter was clogged. That was embarassing, and it cost me $100. This time I thought I better check the air filter myself, so I did. No problem, it wasn't clogged. It wasn't even very dirty, so I put it back. Turned on the furnace and looked for a flashing light indicating a problem. No flashing. Oh listen, hear the burner kick on? Hey, we've got hot air. I fixed it!