Furnace Blower Question
I apologize if I've asked this before. I searched my old threads and didn't see it. I'm looking to fix this thing this week if possible. It's a 1984-era Suburban 35k BTU furnace. From a cold start,...
Forum Discussion
turbojimmy wrote:
Thanks for the replies.
So would a faulty sail switch kill the fan right away? Or just prevent ignition? Whatever it is, it seems to be getting worse. It's getting harder and harder for the fan to start again. It seems that shutting off the TStat and turning it back on works better than moving the temp setting, if that's a clue.
When the fan doesn't run, I can still hear the clicking at the furnace when I move the TStat. So I'm now leaning toward blower or sail switch (if it prevents the fan from running).
1. 30 year old furnace ignition module and wiring will NOT shut the fan blower OFF if no burner lighting and staying lt. UNLESS, someone has replaced the Ignition module with a current that has the Fan switch ON the Ignition module. YOUR old ignition module just had the 4 wire connector and the Spark plug wire to the spark plug. The current that has the built in fan switch will have 2 extra wires connected on the Ignition module with standard wire spade connections. No 2 extra wires and you do not have the current ignition module. You year had a "Time/Delay" relay which is the relay that supplies 12 volts to the fan motor after a 15 to 30 second delay(hense its name) after the 2 wall tstat wires are closed together. The sail switch does NOT prevent your fan from running on your old model furnace. The sail switch comes into action only after the motor is running and stays running. From your description, either the Time delay is bad or the fan motor is bad. Doug
