My furnace is about 10 years old. It runs about 5 to 7 minutes thens shuts off, not heating up to temp on thermostat. It then turns on and cycles over and over until it gets up to the correct temp on thermostat.

Quote: (Is my a coil bad), what coil would you be thinking about?

Thanks for responding. I am talking about the A coil. The furnace run 5 or 6 minutes then shuts off before reaching the temperature on the thermostat. I believe the A-coil ia causing th furnce to overheat and shut off then restrt again over and over again until it reaches the temperature on the thermostat.

There is a coil cleaner you can buy that cleans the coil so you have good circulation blowing ,or pulling air through it, that remedies the overheating of furnace, costs 10-15 bucks