On a cold winter day, you want to stay toasty inside. If your furnace starts blowing cold air, it might have one of several potential problems. While heating repair can address any issue, here's an overview of potential solutions to help you prepare for service. 

The Most Common Causes Behind a Furnace Blowing Cold Air 

1. Clogged Filters 

Gas-fueled furnaces have air filters, while oil furnaces have oil filters. In either case, if those filters become clogged, the furnace won't work properly. 

A clogged oil filter can thwart the ignition process, preventing the furnace from turning on. A dirty air filter will overheat the furnace and automatically turn it off, preventing warm air from circulating through your home. Changing these filters might resolve the issue without requiring heating repair.

2. Faulty Flame Detector 

Gas furnaces often use flame detectors or sensors rather than pilot lights to start the heating process. If the flame detector is covered in dust or grime, it won't be able to sense the flame and start the heating cycle. 

In many cases, a faulty flame detector allows the furnace to start up, but it won't complete the cycle. In this case, you'll get some warm air, but it will quickly turn cold. A technician will clean the sensor so the heating cycle can continue uninterrupted.

3. Clogged Condensate Lines or Valves

Newer furnace models are equipped with condensate lines that help remove moisture from the air, increasing their efficiency. However, if these lines become clogged, the burners stop working and lead to cold air blowing throughout your home. Having the lines cleared can solve the problem. 

If the furnace doesn't turn on at all, it's possible that a clogged valve is preventing gas flow. If the valve is faulty or too dirty, it can keep gas from reaching the igniter, preventing the pilot light from coming on and starting the heat cycle. The valve and ignition can also be affected by a faulty thermocouple, the sensor that controls their function. If the pilot light doesn't come on or doesn't stay on, a technician should replace this part. 

If your furnace is blowing cold air, call the professionals at A & B Heating & Air Conditioning to have it fixed. Based in Burlington, KY, this company offers heating repairs, maintenance, and replacement to homeowners across the tri-state area. Certified by the North American Technician Excellence® (NATE) organization, their technicians provide excellent service. Visit the website to learn more about how they can help, or call (859) 525-0100 to request an appointment.