7 Expert Solutions for a Furnace That Is Blowing Cold Air

Furnace Blowing Cold Air

That’s weird. Your heating system is on … but your furnace is blowing cold air. Really bad news, on a freezing winter day in Brampton!

The good news is that there is help available for your furnace problem. Check out these 7 solutions for a furnace blowing cold air.

Incorrect Thermostat Setting

You thought you set the thermostat to a comfortable temperature. However, sometimes you’re warm and other times you feel a distinctly chilly breeze coming out of the vents. Double-check the thermostat. It may be set to ON, which means that the fan will run all the time, even when the furnace is cycling off.

SOLUTION: Change the setting to AUTO.

Other Thermostat Issues

Your thermostat may be causing trouble for other reasons. 1) If it is battery powered, the battery may have run down. OR 2) If you just installed a new thermostat yourself, you might have purchased a type that doesn’t work with your system.

SOLUTION: 1) Replace the battery. OR 2) Consult an HVAC professional to see whether the new thermostat is, indeed, incompatible with your heating system.

Dirty Air Filter

Is your furnace frequently shutting on and off? Your air filter may have become clogged. When airflow to a gas furnace is restricted due to a blocked air filter, the safety switch will eventually shut off the burners. Since no hot air is being produced, your fan will start blowing cold air.

SOLUTION: Change the filter, if it’s the disposable kind. Or, clean a permanent filter. (Find out how often to change your furnace filter.)

Clogged Condensate Line

As a byproduct of their function, high-efficiency furnaces produce condensed liquid. This condensate normally drains harmlessly away. Occasionally, though, the condensate drain line clogs up, resulting in a furnace blowing cold air and leaking water.

SOLUTION: Contact a heating and cooling technician to clean the condensate line.

Pilot Light Is Out

Your pilot light may be out for one of two reasons. Either it has simply blown out, or it is not lighting correctly in the first place. The latter problem may be due to blockage from dirt and soot, or a malfunctioning thermocouple.

SOLUTION: You might want to try relighting the pilot light yourself … verrry carefully. If it won’t light or it goes out within a minute or so, it’s time to call an HVAC pro.

Insufficient Gas Supply

Obviously, a gas furnace needs an adequate supply of natural gas to work properly. Was your gas supply turned off for any reason? Is your gas valve closed? If the answer to both questions is negative, a blocked line could be interfering with the flow of gas.

SOLUTION: Find a furnace repair expert to inspect and fix the gas line.

Leaky Ducts

Older ductwork tends to develop cracks and leaks as a result of wear and tear. Even though the system is actually blowing warm air, heat is leaking out before it ever reaches you, so you end up feeling as if your furnace is blowing cold air.

SOLUTION: Have a professional conduct duct sealing for you.

Stay Comfortably Warm This Winter

Rely on Dr HVAC for furnace maintenance and repair by our fast, efficient and friendly experts. We care about your home comfort.

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