A Coleman furnace not heating is a remarkably common problem. This does not mean that the brand is of poor quality. Quite the contrary, in fact, Coleman units have a good Energy Star rating and are noted to have 20 plus years of longevity. However, a unit can stop heating for various reasons, several of which are fairly simple to fix on your own.
If the pilot light keeps going out, the furnace will not heat your home. A device called the thermocouple is usually the cause of this heating issue. The thermocouple is a sensor. It sits inside of a steel sleeve located in front of the pilot light.
It must be heated by the pilot light before it can send an electrical charge to the furnace, stopping the gas valve from closing. The pilot light flame should be a minimum of two inches long. You might need to adjust it to meet this size. It should then heat the thermocouple. If the light continues to go out, the thermocouple may need to be replaced. Replacing it can stop the gas valve from closing, thereby allowing you unit to heat again.
A Coleman furnace not heating properly can also be due to a buildup of gunk in the air filters stopping warm air from circulating. Check the filters and clean them if you notice a buildup. You can use a small vacuum to remove dirt.
Rinse the filters with water and let them dry completely before replacing them. If this does not solve the issue, there might be an issue inside the unit itself.
Locate and open the access panel of your unit. You’re looking for the blower motor. It should be at the base of your unit. You will see a belt connected to the fan assembly. Check to ensure it is tightly in place, adjust it if needed. If the belt is frayed, you’ll need to replace it. If this does not solve the issue, then chances are the burners are dirty.
If the cause of your Coleman furnace not heating is dirty burners, a service technician will need to be dispatched. Only a qualified tech can successfully and safely clean the burners. If your warranty is still valid, this fix should be covered.
Originally posted 2011-08-19 08:01:55.