My furnace was acting fine until one day about 2 weeks ago. What happens is that the burner turns n as usual and heats up for about 10-15 minutes. Then the flame shuts off and the blower continues to run (blowing cold air) until I shut of off by the switch in the side. The metal box around the burner is too hot to touch. Could it be overheating for some reason. In order to start it back up, I have to push the reset switch and turn the switch back on. Then the issue occurs again. So far I have had the unit tuned up and the burner was changed out. Any siggesti Ha?
Furnace heats up fine then burner shuts off and blower stays on
Feb 25, 2017
2 Replies
Sounds like the fan limit switch is out of adjustment or gone bad. It's supposed to stop the fan when the plenum temp drops below the set point. That's assuming it's an old furnace without modern electronic controls. And if it is, if you're anywhere that needs heat even a modest amount of time, it's probably terribly inefficient. If it's a modern furnace, then I think they are done based on time now, not temp.
Replacing the fan limit switch worked for me but I ended up getting a new furnace.
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required