Making Sense of a Furnace that Blows Cold Air

Posted: 2022-10-27

Have you noticed the dropping temperatures lately? It looks like there’s no stopping winter from approaching. But what if you’re trying to make your home warm, and instead of achieving that level of comfort, it actually blows cold air? This article aims to help you better understand why this happens and what you can do to restore the heat in your home.

Four Seasons Air Specialists is your dependable heating company in Circle Pines MN. With over forty years of experience in the heating and air conditioning industry, we have helped countless homeowners deal with their heating and cooling problems effortlessly.

Here are some of the most common causes of a furnace blowing cold air.

Wrong Thermostat Settings

Your furnace's thermostat allows you to stay comfortable at home with ease. However, as an electronic device, it can run into some problems at some point. If your unit is blowing cold air instead of hot, your thermostat could be set improperly. Thankfully, dealing with this issue takes a matter of seconds.

When seasons change, it's quite easy to forget your thermostat’s settings. This is especially true during early winter when the furnace is turned on for the first time. If you notice that your heating system is blowing cold air, make sure to check the settings on your thermostat. While it’s unlikely, you may have failed to move the switch to the ‘HEAT’ position.

Try not to keep it set to the ‘ON’ setting, because if you do, the fan will still blow air even when the unit is shut off, which can lead to different problems. For your system to work as it should make sure the thermostat is set to ‘AUTO.’ Following the thermostat’s settings, the furnace will come on at the same time as the fan. This is the ideal, most environment-friendly way to stay comfortable throughout winter.

Overheating Issues

Regardless of what system you are using, overheating is never a good sign. When a furnace overheats, it turns itself on and off unnecessarily. This problem is called “short cycling,” which is the leading cause of high energy consumption and furnace failure. 

One of the possible causes of overheating is a dirty filter, causing your furnace to limit the airflow within the heat exchanger. This lack of proper airflow causes the furnace to use more fuel than usual. Checking and replacing the furnace filter as often as possible can help prevent this problem. It’s one of the easiest things you can do to keep your furnace running effortlessly. Avoid neglecting this problem as repeated overheating can damage the heat exchanger, which not only is an expensive part to replace but can also cause a carbon monoxide leak in your home.

Also, closed registers can cause your furnace to overheat by increasing the pressure in your air ducts. This added pressure slows down your furnace blowers and compromises the airflow within the system.

Moreover, a clogged evaporator coil, a dirty blower wheel, or a broken gas valve can also result in the overheating of your furnace.

Ensure your furnace does not overheat and schedule a routine inspection and maintenance at least once a year. A qualified technician understands your furnace and can detect issues before they escalate and become more severe problems.

Pilot Light Issues

Your furnace's pilot light can also be the culprit. Therefore, check the pilot light on your system and see if it's working properly. If you have a newer unit, it probably doesn't have a pilot light, but if your furnace is older, you can see that this is a small blue flame that’s used to heat the system. Without this light, the furnace simply can't do its job. If this is so, a failing pilot light could be why you’re feeling the furnace blowing cold air.

To rectify this issue, use a lighter to reignite the flame. But if you're uncomfortable doing this step yourself, choosing a professional would be the best course of action. A qualified technician will ensure everything is done the right way (not to mention safety won't be a problem). Once the pilot light is showing a solid blue flame, the system should be ready to give off warm, toasty air!

Ask Four Seasons Air Specialists

To receive outstanding Shoreview furnace repair services, be sure to call us and schedule an appointment with one of our NATE-certified teams. We’d be happy to serve your heating needs this season.