I have a question on the cycling of my NG furnace. When called upon for heat it fires up but only stays on for 3 to4 Minutes then shuts off and stays off for about 5 to 7 minutes. It’s not even close to reaching the temp. that has been called for. Needless to say, this never brings the temp. high enough to make a difference. I thought that maybe it’s a faulty thermostat but I have never had any problem with cooling and short cycling. I have called to get my unit serviced but I am looking for information I why is this so and what component could be causing this problem.
Will be one of the safety switches Hi limit going bad, combustion air pressure switch restricted are the two most common. Do you have a control board with blinking led lights if so read your diagram the blinking lights will correspond to the problem.
In addtion to what Charley said, tell us more and post a picture of the unit with the service doors off. There are some very qualified people here willing to help another HI.
Or the fan not operating. This would cause the “hi-limit” (temperature) switch to shut the burner down until the temperature over the heat exchanger dropped below the preset hi-limit temp of usually around of 200 deg F. Then with the thermostat still calling for heat, the burner would come back on to repeat the sequence.
Furnace short cycling.
No heat to home.
Possible hi temp/fan limit switch problem.
Recommend further evaluation by a qualified service technician.:mrgreen: