I have Trane XL 80 furnace which started to malfunction recently. The heater starts correctly and heats the house for about 5 minutes, after that the flame goes out and does not restart. It would try to restart after a minute or 2 and again the burner would not start. It tries for 2 or 3 times and then quits trying. The blower continues to run as if nothing is wrong. If I turn off the heater and restart after 10-15 minutes, the heater would start fine and then quit in about 5 minutes. Based on scanning various forums it looks like the second stage burners are not coming on. This could be due to a bad controller (one user found a burned out white-rodgers controller, same as mine) or a bad thermal cut off device. I have some technical skills to want to try to see if I can fix this myself. If the controller needs to be replaced, can I do it myself.

Thanks in advance.

If it is in fact the second stage messing you up. Put a jumper from w1 to w2 at the furnace control board and see how long it will run.

if it is infact the second stage messing you up. put a jumper from w1 to w2 at the furnace control board and see how long it will run.

The strange part of this issue is that sometimes the furnace works flawlessly. At the same time it fails to start the second stage at other instances. Would this be consistent with a faulty furnace control board .

Thanks

Could be a faulty control board. Or a pressure switch problem.

could be a faulty control board. or a pressure switch probelm.I guess I should start my replacing the pressure switch. Is that easily replaceable or do I need a trained tech.