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Why Is My Furnace Blowing Cold Air?

Winter is here, which means it’s time to turn on the furnace and enjoy some cozy days indoors. However, sometimes home heating doesn’t always work the way it should after being turned off for some time. Is your heater blowing cold air instead of hot air? While it may be a nuisance, the good news is there are plenty of solutions to fix your chilly air problem. If you are looking for reasons why cold air is blowing out of your vents when the heat is on, our HVAC team has all the answers below.

My Heater is Blowing Cold Air: Reasons and Solutions

Reasons why your heater is blowing cold air.If your residential furnace is forcing cold air throughout your home, here are five potential causes:

1. Faulty Pilot Light

The first thing to check when your gas furnace is blowing cold air is the pilot light. Pilot lights ignite burners, which allow your residential HVAC system to build up and distribute heat. Older furnaces often have problems or damage to the pilot light from normal wear and tear, which can impede heat development.

Try relighting the pilot light to see if that solves the problem. Our furnace installation professionals recommend the following steps:

  • Locate the pilot light assembly and its reset toggle. Reset switches are typically found near the base of the furnace, but check your manual for placement.
  • Turn the reset toggle to the Off position to stop the flow of gas, then wait several minutes.
  • After some time has elapsed, turn the switch back to the Pilot position to allow gas flow back to the pilot assembly.
  • Push and hold down the reset button as you use a match or long-handled lighter to ignite the pilot light.
  • Once a flame is established, release the button. Turn the switch to On, then wait for the furnace to engage.

If you have any issues getting the pilot light lit, or if your furnace still doesn’t blow warm air, it’s time to give our team a call.

2. Dirty or Clogged Air Filter

If it’s been a while since your last routine HVAC maintenance, your home air filters could be clogged and grimy. Dirty filters can hinder proper airflow distribution throughout your residence, which in turn could cause your furnace to overwork and overheat, resulting in cold air.

Check your air filter for signs of dirt, grime, and debris. Replace with a new filter and stay up-to-date with your annual heating and air conditioning maintenance. Don’t have a maintenance plan? No problem! Our installation team can get you set up with one based on your needs.

3.  Clogged Condensate Lines

Some modern furnaces come equipped with condensate lines designed to remove moisture from the air. Over time these lines can become clogged with dust and other particles. If your pipes have an abundance of debris this blockage could disable the burners and lead to cold air coming from your furnace.

It’s best to call your residential HVAC services to help diagnose and remedy condensate line issues. Our NATE-Certified professionals will check the drain pan as well as unclog and clean the lines.

4. Damaged Duct Systems

Cracked and damaged ducts can cause serious issues with your home heating. Gaps, holes, and tears can introduce cold air into your duct system and let warm air escape. Even if your furnace is in top shape damaged ducts can cause cold air to distribute through your residence.

Since ducts are not always easy to get to and are intricate systems, it’s best to let the HVAC experts handle this one. Minor damage might be easily fixed by professional duct sealing. If there is significant damage, or your system is over ten years old, it might be time for a replacement.

5. Incorrect Thermostat Settings

Sometimes a furnace blowing cold air is something as simple as the wrong thermostat setting. 

Check to make sure your thermostat is set to Auto, as opposed to On. If left in the On position, your furnace will run continuously, even when it’s not producing heat.

Professional Heating Repair in Portland, Oregon

At AAA Heating and Cooling, we are your go-to residential HVAC servicing and installation company in the Portland metro area. Call our specialists if you aren’t sure what might be causing your furnace to blow cold air.  Contact us today for a full consultation!