Why is My Furnace Blowing Cold Air? - Sun Heating & Cooling, Inc.

Why is My Furnace Blowing Cold Air?


You may not know why your furnace is blowing cold air, but one thing’s for sure, “Brr!” Today we’re going to show you how to fix it.

There are several reasons, all of them very different from one another, that could be causing this problem:

1. The thermostat is set wrong. And when we say that, we don’t mean to insult your intelligence! A lot of people accidentally have the thermostat set to “On” rather than “Auto,” which will cause the fan to blow air all the time, even if there’s not a heating cycle. That means some of that air could end up being cold air, and plus, you’ll spend more money by having your furnace fan blow air 24/7!

2. Turning your furnace on for the first time this year. Although we know that this possibility would never apply in February, it’s something to consider if your furnace starts blowing cold air in the future, like next fall. If it’s your first time turning the furnace on, it’s normal for cold air to come out of your vents for a little while, while the components are getting started and the burners are firing for the first time in a long time. This process might take about 15 to 20 minutes. If you don’t have hot air after that, then you’ve got a problem!

3. Your filter is dirty. We know we’re like a broken record saying this all the time, but it’s just SO important: don’t forget to change your air filter! You already know that a dirty, clogged air filter messes with air circulation in your home and makes your furnace work harder. But it can cause your furnace to blow cold air as well. This is because a dirty air filter can cause the system to overheat, which causes cold air, because the furnace has shut down as a safety measure. Please, just don’t forget to change your air filter!

4. Leaky ducts. If your air ducts have leaks and gaps in them, that could cause your system to blow cold air. Too much of the heat is escaping through all these holes in the ducts. This is an issue for the professionals to tackle, because it can be complicated to find the leaks and seal them yourself without having the proper equipment!

5. Not calling Sun Heating and Cooling. Okay, so that might not be the direct cause of cold air coming out of your vents, but if you don’t call us, we can’t help! We’ll inspect your system and find out what’s going on, so the furnace in your Oakland County home won’t blow cold air anymore. Just give the pros at Sun Heating and Cooling a call to get things back up and running! Contact us online or call now: (248) 986-1506

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