Why Is My Furnace Blowing Cold Air?

During this chilly Sacramento winter, furnaces are more important than ever. If you’ve noticed your furnace suddenly blowing cold air, do not despair. Not only is this issue common, it’s also treatable. Read through these 3 potential causes to learn more about why your furnace may be blowing cold air.

Incorrect Thermostat Settings

Most thermostats have the setting options On, Off, and Auto. On Auto, your furnace only runs during a heating cycle when there is hot air to push out. If your thermostat is set to On, however, the furnace will run even outside of the heating cycle when there’s no hot air to release, resulting in cool air coming out. The simple solution is to turn your thermostat to Auto. 

Dirty Air Filters

As air filters get older, more dust and debris build up on them, blocking the passage of air. The hot air heats up the system as it struggles to get through the filter and reduces and the limit switch can shut down heating cycles early. Changing your filters regularly can prevent your furnace from blowing cold air. If you sign up for a preventative maintenance program with Express Refrigeration, our technicians will take care of filter changes for you so you never have to worry about forgetting to change them.

Pilot Light is Off

Many older furnaces have a pilot light that heats the air. If the pilot light goes out, the fuel will not combust, the air won’t heat, and the air expelled by the furnace will be cold. If your pilot light is off, you can turn it back on by following these steps:

  1. Turn the gas valve Off and wait 5-10 minutes to allow any gas to dissipate. 
  2. Turn the valve to Pilot and use a lighter to relight the pilot light. 
  3. Once lit, turn the Valve to On.

If you are unable to complete these steps, keep your furnace off and call Express Refrigeration and we will send an HVAC technician to help.

While these three issues are common causes of a furnace blowing cold air, there are other possibilities as well. To get an accurate diagnosis and appropriate repairs, call a licensed HVAC technician. Express Refrigeration is here to help you with your furnace and AC needs, so call today!