Why Is My Furnace Blowing Cold Air? And What You Should Do About It – Burnaby Furnace Repairs

Turning on your furnace during a cold Metro Vancouver morning only to feel cold air blowing from the vents is frustrating—and a little alarming. A furnace blowing cold air isn’t just a comfort issue; it can be a sign of a furnace system malfunction that needs immediate attention.

While some homeowners may be tempted to troubleshoot on their own, furnaces are complex and potentially dangerous if handled improperly. In almost every case, the best course of action is to call a qualified HVAC technician to assess the situation. But before that, it helps to understand what might be going on—and what you should absolutely avoid doing.

What Causes A Furnace To Blow Cold Air?

Several factors can cause your furnace to push cold air through the vents. Some are relatively simple; others require professional repair. Understanding the possible reasons helps you avoid guessing games or risky DIY attempts. Here are some of the most common causes:

• Thermostat Settings – One of the first things to check is your thermostat. If it’s set to “on” instead of “auto,” the blower fan will run non-stop—even when the furnace isn’t heating. That means you’ll feel air coming out of the vents, but it may not be warm.
• Clogged Air Filter – A dirty or blocked filter restricts airflow, which can cause the furnace to overheat. In response, the safety system may shut down the burners while still running the fan, resulting in cool air.
• Pilot Light Issues (In Older Furnaces) – If you have a furnace with a standing pilot light and it goes out, the system won’t be able to ignite the burners. No flame, no heat.
• Flame Sensor Malfunction – The flame sensor ensures that burners stay on after ignition. If this component is dirty or faulty, the furnace may shut off the burners shortly after starting, while the fan continues to run.
• Leaky Or Damaged Ductwork – If your ducts have gaps or cracks, the warm air could be escaping before it reaches your living space, leaving only cool air to circulate.

In all these cases, trying to diagnose or fix the issue on your own could lead to more serious damage—or even safety risks. Always contact a professional furnace specialist to inspect and repair the system properly.

What Not To Do If Your Furnace Is Blowing Cold Air

Wanting to get your heat back quickly is understandable. But trying to “fix” your furnace without proper training is never a good idea. Here’s what you definitely should not do:

• Don’t take apart the unit – Opening panels or accessing internal components without the right tools and knowledge can void warranties or cause damage.
• Don’t override safety mechanisms – If your furnace has shut down a heating cycle due to a detected issue, overriding it could lead to overheating or even carbon monoxide risks.
• Don’t keep it running when it’s clearly not working – If the system is blowing cold air, turning up the thermostat won’t help. It only strains the equipment.
• Don’t assume the problem will go away on its own – Furnaces rarely fix themselves. Ignoring the issue can lead to more expensive repairs later—or a complete system failure.

The safest and smartest decision is to call a licensed HVAC professional who can diagnose and resolve the issue safely.

Burnaby Furnace Repair And Replacement

And, of course, most importantly: keep your device’s preventive maintenance up to date. We at Nation Furnace Heating & Air Conditioning HVAC have qualified professionals to help you through the entire process, whether repairing or replacing your furnace according to your family’s needs. To contact us, click here.