My Furnace is Running but Not Heating

Is your furnace running but not creating warm air and heating your home? If so, below is a list of possible culprits that you can check yourself before calling an HVAC technician. Some of these you can fix yourself, others you will need to consult a professional.

Check the Thermostat

It might seem too simple, but if your furnace is not creating heat, always start with checking the thermostat. The batteries might be dead or an adjustment could have been made without you knowing and the fix is as quick as a setting change.

Check the Filter

A dirty filter can wreak havoc on your furnace. Not only will it obstruct airflow, but it will not clean the air before it runs through the unit and inhibit the unit from doing its only job. If your filter is dirty, replace it or clean it and test your furnace.

Inspect the Pilot Light

Gas furnaces rely on a standing pilot light to operate. If the pilot light somehow goes out, the fan may run but the furnace will not warm the air. If you don’t see a blue flame near the bottom of your furnace, you will need to access the reset switch and use a lighter to light the pilot again. If this happens multiple times, you should call an HVAC pro.

Check the Condensate Line

High-efficiency or condensing furnaces produce condensation during combustion. This excess moisture falls onto a drip pan and is drained outside of the home through a condensate line. These condensate lines can become clogged with dirt and grime, especially if you do not keep up with furnace maintenance and filter changes. If the line becomes blocked, the water will end up back in the furnace, which will trip the overflow kill switch and shut down your furnace. Your furnace will either not turn on or simply blow cold air.

Inspect the Burners

The burners on gas furnaces are responsible for delivering and adjusting the flow of gas to keep it lit when running. If your furnace has not been cleaned in a while, dirt and debris can collect on the burners, preventing your furnace from getting enough gas to burn and warm the air. This is a fairly simple repair, but always consult a professional if you are not familiar with the equipment.

In many cases, cold air blowing through your vents is an easy problem to fix that you can do yourself. If you cannot figure out why your furnace is running but not heating the air, it is time to call an HVAC expert to diagnose your furnace.

In need of a furnace diagnosis, cleaning, repair or replacement? Grand Home Services in Aurora provides all these services and more throughout the Denver Metro Area. Call us or contact us online today!