Why Is My Furnace Blowing Cold Air?

A common question we hear from homeowners is, “Why is my furnace blowing cold air?”
Because a furnace is responsible for creating warm air for a home, it is a bit concerning if cold
air is blowing out of the furnace and into the air ducts and air vents. Depending on the type of
furnace you have (gas furnace, electric furnace, wood burning furnace, or an oil furnace) will
direct you to the root of the cold air problem. But first, you should always check the thermostat
to make sure you’re set up properly!

Why A Thermostat Matters With This Problem

Sometimes, the problem with a furnace blowing cold air isn’t because of the furnace itself.
Sometimes, it’s actually to do with the thermostat. If your thermostat isn’t properly set the cold
air can’t be stopped. First, make sure that your thermostat is set to AUTO instead of ON. Why
should you do this? Well, because if you keep your thermostat set to ON, the air conditioner
will constantly blow out cold air.

Instead, you should ensure that the temperature you set your thermostat at is just above the
temperature you want your house to be at, and make sure to keep the thermostat on AUTO. If
you keep the thermostat on auto, the cooling air will only kick in if the house temperature goes
above what you have set.

The other reason your Thermostat can be causing cold air is because of the batteries. We say it
all the time, but we’ll say it again. Check your thermostat batteries! If your thermostat doesn’t
have enough battery power, it may not function the way it’s supposed to.

Checking In With Your Furnace

If you did an end of summer check in with your furnace, you’ll likely nix any heating problems
before the colder months set in. But if you’re experiencing a furnace blowing cold air, it could
be from the heating mechanism. This doesn’t necessarily apply to electric furnaces, but for a
gas furnace, you should be checking to see if the pilot light is still burning. A pilot light is the
small flame that continually burns so that your heater can ignite easily. If this light goes out for
whatever reason, you can see a drop in air temperature.

For oil burning furnaces, you need to also ensure that the heat is able to move properly through
the system and into the air ducts. Oil burning furnaces come with a filter, which filters out
particles as it churns out heat. Make sure your filter isn’t clogged up, or you may be feeling the
cooler air as well.

Make Sure Your Ducts Are Properly Sealed

A final, and very important reason you find your furnace may be blowing out cold air, isn’t to do
with the heating mechanisms at all! There’s a reason we recommend checking in on your ducts
every Fall. That’s because you may be losing heating through the ducts if they are not properly
sealed, giving the impression that your furnace is blowing out cold air when the heat’s
disappearing before it gets to the vents.

Unsure? Always Check in With Air Conditioning Experts!

No matter the cause of your cold air in the cooler months, it can be a frustrating problem to
solve. When it comes to fixing furnace problems, trust in the Applewood Air experts. An expert
can take a look at your furnace, your air ducts and even the specs of your house to determine
the exact cause of your cold air. In some cases, it may even be because the furnace and heating
system is not large enough for your home! For more information, please don’t hesitate to get in
touch with Mississauga’s HVAC experts—Applewood Air.

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