[antiqueynot]

This is a 6 to 8 year old (I believe) propane, forced hot air, horizontal, updraft unit. It is in a presently unoccupied apartment, but I would like to repair it so the apartment pipes don't freeze. So far I replaced the ignitor about two weeks ago and thought all was well. I noticed about a week ago that the circulation fan was running continuously, but couldn't get to check until today. I found that the diagnostic light was blinking 9 times which the chart says "Check Ignitor". I also found that the flame sensor wire was charred for the 2 inches before it conects to the sensor. I repaired that wire by cutting off the cahrred section and put on a new connector. I have contiuity from the sensor to the board. I also cleaned the sensor. I tried removing the recently replaced ignitor, it had a white, ashy appearance, cleaning the surface, and reinstalled. It does not glow when initialized. I measured 2.5 volts at the ignitor conector. I tried cleaning and installing the previously replaced ignitor, but no joy. I intend to get new ignitor and flame sensor on Monday but it's quite a drive to the supplier and if I need to get a control board, I'll bite the bullet. Thanks for any help or guidance that you can give,
Tony AKA Antiqueynot

[T-Top]

Never touch or try to clean a hot surface ignitor. If you do its going bad. The oil from your skin will take it out. The chared flame sensor wire is a sign of burner roll out and heat build up in the burner compartment. No need to replace the flame sensor unless the ceramic around it is broke. Sensors don't go bad.

[antiqueynot]

T-Top,
Thanks for answering. I did not touch the ignitor with my fingers, just used Scotch-Brite and some 1500 grit wet or dry sandnpaper to attempt to remove the ashen coating. I feel that I messed up the ignitor and the flame sensor by letting the furnace continue to run and attempt to restart for several days. What does the charred 2 inches of wire at the flame sensor indicate? I did cut off the charred bit, put on another connector and have continuity through the wire from the connection at the citcuit board to the sensor. My Trane parts supplier is an hour away so I want to minimize trips. Thank for any info you can supply. I'm a pretty good auto mechanic, know a fair amount about oil fired hot air furnaces but don't know squat about propane stuff! Any advice is appreciated. If the funace worked for a while when I replaced the ignitor a couple of weeks ago, and I smell propane at start up now, and both the circulation fan and inductor(?) fan work, are they good signs?

[antiqueynot]

T-Top,
I see that you already answered both of my questions. It would appear that I messed up the newly installed ignitor. I will get another on Monday even though I didn't touch it, I did try to clean it with Scotch-Brite and 1500 grit sandpaper. I cleaned the surface of the flame sensor and since the ceramic is good I may not need to buy one of those. I'm sorry but I don't know what "burner roll out" is. Is it flame coming back from the burners? I didn't see any evidence of flame on other wires or anything else near the sensor wire. The local Trane parts supplier is an hour away so I just want to minimize trips to get parts, but also don't want to waste money on parts I don't need.