April 30, 2021

5 Reasons Why Your Furnace is Blowing Cold Air and How to Fix It

You probably don’t think about your furnace much until it’s not working properly. One of the most common problems we encounter is a furnace blowing cold air. Many times, this problem can be fixed inexpensively on your own. Other times you might need professional help from our furnace repair in Cheyenne, WY, and surrounding areas.

Here are five of the top reasons why your furnace is blowing cold air and how you can fix them.


1. Wrong Thermostat Setting

If your furnace is blowing cold air sometimes or your furnace is blowing hot air and then cold, your thermostat settings could be to blame. Make sure it’s set to “heat” and “auto” to avoid having your furnace blowing cold air on heat.

Otherwise, your furnace’s fan will be running all the time and circulating cold air when the furnace isn’t on. This is often the instance when we get a call that someone’s gas furnace is blowing cold air and won’t shut off. Or that a furnace intermittently blows cold air.

If you have a programmable thermostat, now is a good time to think about upgrading to a smart thermostat. With a smart thermostat, it’s easier to keep your furnace on the correct settings and enjoy energy-efficient heating with little effort on your part.


2. Clogged Air Filter

If your furnace is blowing out cold air, we recommend checking your air filter. Flat filters should be changed once a month and pleated filters should be changed every three months.

A clogged or dirty air filter can restrict your furnace’s airflow and affect your comfort. If this goes unchecked, your furnace will begin shutting down prematurely to avoid overheating and cracking the heat exchanger, which could cause a carbon monoxide leak.

Not sure when you last changed your filter?

  • Turn your furnace off at the thermostat and its switch, which is located on or near the furnace.
  • Remove the filter and hold it up to light.
  • If you can’t see light through the filter, replace it.

Once you replace the filter, your furnace should begin operating normally again. If you’re continuing to experience your furnace only blowing cold air, call us at 307-778-0515 for help.

With your hectic schedule, we know that staying on top of replacing your filter is a challenge. That’s why we recommend scheduling annual furnace maintenance, which may also help reduce your chance of breakdowns and boost energy efficiency.


3. Electronic Problems

With a gas furnace blowing cold air, it could mean there’s a problem with your furnace’s electronic control panel.

You can try resetting your furnace by following these steps:

  • Turn off its switch. This switch looks like a light switch and is located on or near the furnace.
  • Wait a few minutes.
  • Turn the switch back on.
  • If this was the problem, your furnace should begin blowing warm air once it resets. It may take a few minutes for it to turn back on.


4. Pilot Light Issues

Newer furnaces use electronic ignition. But if you have an older furnace, it relies on a pilot light to ignite fuel. If the pilot light is out, you might experience your gas furnace blowing cold air. Here’s how you can resolve the problem:

  • Turn your furnace off at the thermostat and its switch.
  • Turn the reset switch to “off” on the pilot light assembly.
  • Wait 15 minutes to allow gas to escape.
  • Turn the reset switch to “pilot” while using a long lighter at the pilot to light gas.
  • After you light the pilot, turn the switch to “on.”
  • Turn your furnace back on. It may take several minutes for it to start.

If your pilot light won’t stay lit, something else might be wrong. We offer 24/7 emergency service, so call us at 307-778-0515 anytime for assistance.


5. Leaky Ductwork

Your furnace relies on ductwork to deliver warm air. When that ductwork gets old or separates, your comfort can suffer. As a result, the air might not feel as warm once it finally reaches your rooms. Because your ductwork is in tight or out-of-sight places, like your attic or behind walls, you’ll need professional help to find and repair ductwork leaks.


Our Pros Can Solve Your Furnace Blowing Cold Air Problems

If you’ve made it through our checklist and your furnace still isn’t working right, AC Mechanical can help. With our affordable 24/7 emergency furnace repair from friendly, licensed professionals, we’ll have your heating running again quickly. Give us a call at 307-778-0515 to schedule your appointment now!

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