What if my furnace is blowing cold air

Thermostats make our lives so much easier. Air filters catch dust and debris we generate in our homes—that means they need to be changed on a regular basis. An overly clogged air filter will limit airflow to your furnace and could cause it to overheat and turn off. This is something you can check yourself — just make sure your furnace is turned off before you look at or remove the filter from the air handler.

Make sure your air filter is changed every 90 days. If you have forgotten about it, now is the time to get rid of that dirty air filter! Dirt buildup — if your filter was clogged, chances are dirt and debris worked their way into other parts of your furnace. If that dirt is in moving components, like the blower, it can cause your furnace to overheat.

This may be the source of your furnace problems, particularly if you have an older furnace. Age — as a furnace ages, it stops performing as well.

Typically the furnace burner itself, the flame sensor, or the gas supply pipe are to blame. A clog in the condensate line will prevent your furnace from igniting. No ignition means only cold air coming through your vents. This problem requires a visit from your HVAC repair technician. Your furnace blowing cold air could be caused by hot air escaping through holes in the duct work that carries the heat throughout your building.

Have an expert inspect your ducts along with the furnace. If your furnace starts blowing warm but then quickly turns cold, the flame sensor may need attention. If the furnace burner itself is neglected, accumulated dust and grime can cause trouble igniting. Have your system professionally cleaned to take care of this problem. Many of the causes of furnace problems can be prevented with regularly-scheduled cleaning and maintenance.

The best service providers can customize a plan for your needs and your budget. Incorrect thermostat setting. Other thermostat issues. Empty oil tank. Problem with computerized controls. Overheated furnace. Extinguished pilot light. Valve problem. Faulty thermocouple. Clogged oil filter. Faulty electronic ignition. Coolray is your Atlanta-area home comfort expert with specialists in heating, air conditioning, air quality and plumbing. Have more questions? Related article: Help!

Well, it could be multiple issues; some of them you can solve yourself. So before calling a professional for help, try these 4 furnace troubleshooting tactics. Check the pilot light Do you have an older furnace with a standing pilot light? Also, this image may help:. You should see a knob with these 3 settings: "Pilot" "Off" "On" Step 3: Turn the knob to "off" and wait minutes This will shut down gas coming through the pilot.

Step 5: As you press the knob, hold a lighter to the pilot opening until the flame lights When the flame lights, it should be a steady blue cone that hits the middle of the thermocouple a small copper bar. Step 7: Turn the furnace on at the thermostat Turn your thermostat back to HEAT and ensure that the temperature is set 5 degrees below room temperature. Check your condensate line Do you have a high-efficiency furnace? Let us explain.