Why Is My Furnace Blowing Cold Air?

February 23, 2023
1seodev
Blog, Furnace

When old man winter rolls around, you expect your heating system to generate hot air and keep your home comfortable until the end of the cold season. So if you’ve discovered your furnace is not blowing hot air as it normally should, it’s understandable if you’re concerned.

Gas, propane, and electric furnaces can experience unexpected problems throughout their lifetimes. These heating systems contain many crucial components that can wear down over time. Unfortunately, this also means that there can be many reasons why your furnace is blowing cold air.

Don’t worry! We’ll discuss some of the most common causes of this troublesome problem to help get your furnace back on track.

Your Furnace Filter Needs to Be Replaced

When you find your furnace not blowing hot air like you expect it to, it’s easy to jump to conclusions. You might think that your heating system needs to be repaired or replaced — when you may just have to replace the dirty air filter.

Furnace air filters are incredibly important because they collect and trap airborne contaminants, so they don’t circulate through your home. These harmful particles can include dust, pollen, and pet dander. Unfortunately, the filter can get so clogged that it restricts the airflow coming and going from the furnace. Poor airflow can strain the heating system excessively and lead to problems, such as insufficient heating. In the end, you may also need a furnace repair or replacement.

The good news is that replacing a dirty or clogged filter is a simple process! This easy maintenance task is also included in most maintenance services, so don’t hesitate to call a professional technician to schedule regular maintenance for your furnace.

Your Thermostat Is Set Incorrectly

Did you know that your thermostat’s fan setting could be why your furnace is blowing cold air? You should check that your thermostat is currently set to “auto” instead of “on.” If the setting is currently set to “on,” this means that your furnace will continue to blow air at all times, all around the clock — whether the air is hot or cold.

The good news is that this particular problem is easy to fix! You don’t need to worry about scheduling a furnace repair in Mankato, MN, or plan for a sudden replacement. Changing your thermostat’s setting will only take a few seconds and can make a difference in your comfort.

You’re Dealing With a Control Board Issue

Your furnace’s control board is responsible for controlling all of the heating system’s internal components. If the circuit board starts malfunctioning or becomes faulty, this can cause your furnace to blow cold air. That’s because your heating system relies on the control board to start a heating cycle.

When it comes down to it, don’t overlook the possibility of a circuit board issue being why your furnace is blowing cold air. If you think you’re dealing with a control board problem, don’t hesitate to call an HVAC technician for help. A professional will diagnose the issue and provide a solution, depending on what the problem is.

Your Gas Furnace Has a Dirty Flame Sensor

Every gas furnace has a flame sensor. This critical component, which sits near the pilot light, detects whether or not a flame is present. When the flame sensor detects a flame, the gas valve will open, and the burners will ignite.

If this sensor becomes dirty over a period of time, this can significantly prohibit its ability to detect a flame. As a result, the burners won’t be ignited, and the furnace will only blow cold air instead. So when you find your furnace not blowing hot air, it might be time to put some suspicion on the flame sensor.

Your Home’s Air Ducts are Leaking

When you find your furnace not blowing hot air, you might be surprised to learn that your ductwork could be to blame for this problem. Your air ducts are specifically designed to work hand-in-hand with your HVAC system. Once your furnace starts a heating cycle, the warm air it generates is sent out into your home via your ductwork.

Unfortunately, your air ducts can sustain regular damage over the course of their lifetime. As such, the warm air traveling through them can escape through holes and gaps. In the end, it might seem like your furnace only blows cold air, as the warm air will have escaped by the time it reaches your vents.

Keep Warm With Help From Our Furnace Specialists!

As you can see, there are many potential reasons why your furnace is blowing cold air. If you think your heating system needs a repair or replacement, turn to the experts at Connors Plumbing & Heating! Our friendly and knowledgeable technicians specialize in all furnace makes and models, so you can rest assured that your services are in capable hands.