||Possibly the electrical system that provides power to your furnace has shorted or blown the power switch.
||Reset your Keeprite furnace’s circuit breaker. If it is blown, you’ll have to replace it.
||The furnace’s igniter could be cracked or faulty.
||Check if the part has cracks. If it does, then replace the igniter. If it doesn’t, use a multimeter to test for continuity.
||The thermostat of your furnace might be adjusting incorrectly.
||If your thermostat has an adjustable calibration scale, adjust the heat anticipator. If this does not address the problem or you don’t have a scale, you may have to replace the thermostat.
|Not blowing hot air?
||The blower motor may have burnt out. If this doesn’t seem likely, then the connecting belt may have broken.
||Test to see if power is reaching the motor. If it does, but nothing is running, the motor has likely failed and needs replacing. If the motor runs but air doesn’t move, the connecting belt has probably broken. You’ll have to replace the belt.
|Blowing too much air?
||If the relay that regulates the blower motor on the control board has failed, it will continually send voltage to the motor.
||Replace the control board.
||The contact that controls the blower motor on your thermostat may be stuck closed. The result is that the blower motor will run continuously.
||Use a multimeter to check for continuity. If the issue is the thermostat, replace it.
|Starting and then stopping shortly after?
||Your furnace’s flame sensor monitors the burner, detecting if a flame is present. It's either defective, or there is debris, and won't be able to detect a flame.
||If dirty, carefully clean the sensor using a fine abrasive pad. If not, replace the flame sensor.