When a furnace just clicks, it’s time to get it fixed. This happens when the main seal is dirty or clogged and it’s putting too much of a load on the motor. If you hear a snap, crackle, or squeal, this could be the problem. You can have it professionally repaired or you can fix it yourself at home.
The first thing you want to do is shut off the power to the furnace. Next, turn off the gas source. Remove the wiring harness and place it somewhere safe and secure. Keep a bucket of water nearby, especially for grease deposits and engine oil. If the issue is right in the motor, the water could scratch the inside of the furnace. Take the radiator cap off to clean it and give you a better look.
Check the oil level, making sure it is low. The motor might need lubrication with your hand or with a small screwdriver. Now, turn the motor upside down and unscrew the screw. If the seal is all dirty, the motor will need to be taken apart to get it cleaned up. Take off the cover and let the motor dry completely. Replace the cover and reinstall the screws.