Why Your Furnace is Blowing Cold Air
When winter arrives, the last thing you need is your furnace going out. The furnace of your HVAC system provides heat throughout your entire home, so during the winter, it's very important that it’s working properly. I will explain also how to troubleshoot a furnace as well.
Your Furnace Needs To Warm Up
When you first turn your furnace on its completely normal to feel a blast of cold air. Your furnace needs time to warm up and is expelling cold air out of the vents. Just give it a moment and if you feel warm air you are golden.
Thermostat is Set to On
If you can still feel cold air blowing after about 15-20 minutes after you have turned your furnace on, check your thermostat the unit fan may be set to on. This makes your furnace blower constantly run, even when your furnace isn’t heating the air. Your furnace blower is the fan inside the furnace that helps expel carbon monoxide out of the exhaust vent of your furnace. By setting the fan to “auto” the fan will only blow when the furnace is heating air.

The Flame sensor is dirty
Pilot-less ignition furnaces use a flame sensor (pictured below) to keep the furnace burning once it cycle starts. If your flame sensor is dirty your unit will begin to turn on and heat up, but then very quickly turn cold. To clean your flame sensor we recommend employing the help of a licensed HVAC technician.

The Pilot Light is Out
The older your furnace is, the more likely your pilot light has stopped working. Which in turn will cause your system to blow cold air. To reignite your pilot light we recommend a licensed HVAC tech, to ensure your security and safety. If it doesn’t stay lit, this most likely means it's time for your HVAC to do some routine maintenance. There could also be the thermo-couple which is the copper rod the pilot flame hits. (image below)

Check Your Air Filter
Your air filter should be changed out every 1-3 months on your HVAC system. If your air filter is clogged, it can cause your furnace to run improperly. A dirty filter can limit the airflow going into your system. In turn, this can cause your furnace to run longer until it overheats from exertion. If your furnace overheats it will do nothing but blow cold air. Changing out your filter will then resume the correct airflow to your system, and it will be much less likely to overheat.

If you have gone through all the steps above and still can’t figure out what’s wrong with your furnace be sure to get in contact with a licensed HVAC professional. If you live in Huntsville, AL or the surrounding areas we would love to assist you here at A- Plus Comfort LLC. Give us a call at (256)585-2550 and one of our licensed tech will be happy to assist you with any questions or concerns you may have. Thank You!







