Is Your Furnace Blowing Cold Air? Here's Why

Posted: 2021-12-16

Dealing with a furnace that fails to deliver heated air can be quite frustrating. But it helps to know why it’s acting in such a way to know what to do next.

Four Seasons Air Specialists is your total heating company in Grant MN. We help homeowners fix any issue their furnaces are suffering from.

In this article, let’s talk about four reasons why your heater blows cold air.

Your furnace is overheating.

Any piece of equipment that overheats is a reason for concern, and heating systems are no exception.

If your furnace tends to turn itself on and off frequently, overheating can be the reason. This issue is called “short cycling”, which happens when your furnace switches itself on or off without reaching the set temperature. You will notice your home isn’t as warm as it should, leaving you and your family cold and uneasy.

Overheating causes your energy bills to rise, makes your furnace less efficient, and is also potentially dangerous, particularly if you’re running a gas-fired unit. Several reasons can cause your furnace to overheat, which include dirty air filters, filthy blower wheel, blocked vents, clogged evaporator coil, or a broken gas valve.

Inadequate airflow can also cause your furnace to turn on and off. Dirty filters limit airflow to the heat exchanger, causing it to operate at higher temperatures.

Also, closing more than half of your vents or heat registers, increases the pressure in your air ducts. Doing so slows down your furnace blowers and compromises airflow in the heat exchanger, causing your unit to overheat.

Another reason for your furnace to overheat is a filthy blower wheel. It adds pressure to the furnace, which curbs your unit’s airflow.

If you have a newer furnace, it is likely to have a built-in limit switch that powers off the unit when it gets too hot, preventing further damage.

Regardless of your furnace’s age, it is always a good practice to inspect your filters at least once a month and replace them when they are too dirty. This step is the simplest thing you can take to keep your furnace in good shape and avoid enduring the cold.

If furnace overheating is a constant problem in your home, call a qualified professional to determine the issue and apply appropriate solutions.

Your furnace has electrical issues.

Even if you have a gas-fired unit, your heating system still needs electricity to function. Simple issues such as a tripped breaker inside your electrical panel can cause several problems, including your furnace blowing cold air. A tripped circuit breaker can cause your furnace to not turn on at all. Electrical issues can also lead to a pilot light not turning on, leaving you in the cold.

Most of the time, resetting the circuit breaker fixes the problem. But if the problem remains unresolved, you should call a qualified technician as it could be a sign of a more serious electrical problem.

Your home has a low supply of gas.

If you have a gas-fired unit and it blows cold air, chances are there is a serious issue with the gas supply line in your home. Most furnaces are programmed to shut down if they aren’t receiving enough gas to deliver the required heat. Unfortunately, fixing this problem isn’t as easy as changing filters. It’s best to call a professional HVAC technician to check the gas line and repair the issue.

Avoid working on it by yourself, especially if you’re not trained. Doing so puts yourself and your family at risk of an accident, like a fire. For your safety, contact a trained individual to perform the repair job.

The condensate lines are restricted.

Your furnace blowing cold air could mean there is a blockage to the condensate lines. Certain furnace models are equipped with condensate drain lines that help take away excess moisture. If these lines are clogged, then the system will deactivate the burners and cause the unit to blow cold air into your home. Clogged condensate lines require professional expertise, so we recommend calling a qualified technician to perform the de-clogging task.

Leave it to the Pros

If you need help fixing your malfunctioning furnace, call Four Seasons Air Specialists. Our teams of Mahtomedi air conditioning repair experts will restore the heat in your home in no time.