As the temperature drops, a furnace blowing cold air can be a frustrating and worrisome problem. At Affordable Comfort, we’ve seen this issue countless times, and the good news is that it’s often something that can be resolved quickly. Let’s dive into the most common reasons your furnace might be blowing cold air and what you can do about it.
Thermostat Settings
Before assuming the worst, check your thermostat. Is it set to “ON” instead of “AUTO”? When set to “ON,” the fan will blow continuously, even when the furnace isn’t heating. Switch it to “AUTO” so it only runs during heating cycles.
Pro Tip: Ensure your thermostat is set to “HEAT” and not “COOL.”
Dirty Air Filter
A clogged air filter restricts airflow, causing the furnace to overheat and shut off the burners as a safety precaution. The fan will keep running, but only cold air will come through the vents.
Solution: Check your air filter monthly and replace it every 1-3 months, depending on usage and type.
Pilot Light or Ignition Issues
For older furnaces, a pilot light that has gone out will prevent the furnace from heating. Newer models with electronic ignition may face issues due to a malfunctioning ignitor.
Solution: Try relighting the pilot light if you have an older system. If it doesn’t stay lit, it could be a gas supply or thermocouple issue—this requires professional attention.
Insufficient Gas Supply
If your furnace is powered by natural gas, a disruption in the supply could prevent it from producing heat. This could be due to a closed valve or a problem with the gas line.
Solution: Ensure the gas valve is open and contact your gas provider if you suspect a supply issue. For anything beyond basic checks, contact a licensed HVAC technician.
Ductwork Problems
Leaks or blockages in your ductwork can result in cold air mixing with the warm air or prevent the heat from reaching your vents altogether.
Solution: Schedule a professional duct inspection to identify and seal leaks or clear blockages.
Furnace Overheating
If your furnace is overheating, it will shut down to protect itself, leaving the fan to blow cold air.
Solution: Overheating often points to airflow issues, such as a dirty filter or blocked vents. If the problem persists, a professional inspection is recommended.
When to Call a Professional
While some issues can be resolved with simple troubleshooting, others require the expertise of a licensed HVAC technician. At Affordable Comfort, we specialize in diagnosing and repairing furnace issues in Barrie quickly and effectively, so you can get back to enjoying a warm, cozy home.
Prevent Future Issues with Regular Maintenance
The best way to prevent problems like a furnace blowing cold air is through routine maintenance. Affordable Comfort offers Comfort Club Memberships, which include annual maintenance, priority service, and discounts on repairs—keeping your heating system running smoothly all year round.
If your furnace is blowing cold air and you’re unsure where to start, don’t hesitate to reach out to Affordable Comfort. Call us today or book a service online. We’re here to make home comfort easy!
