Although Phoenix, AZ is known for its scorching summers, the desert winters can have their share of cool weather. If your household heating system suddenly starts blowing cold air, it’s going to impact your comfort. When a heating system is blowing cold air instead of hot, there are several possible causes. Let’s take a look at the most likely explanations for this frustrating household problem.

1. Dirty Air Filter

One common cause for a furnace blowing cold air is a clogged or dirty air filter. As the heating system runs, the filter consistently catches airborne contaminants. Air filters only have so much space, and they eventually become too packed with contaminant particles to function correctly. Once that happens, the furnace’s airflow can become restricted, which can cause the appliance to distribute cold air throughout your home. Clogged air filters can also worsen the health and efficiency of your HVAC system, leading to costly and inconvenient repairs. So, if your heating unit is blowing cold air instead of warm, switching out the filter for a clean one is a good troubleshooting option.

2. Thermostat Set Incorrectly

If your furnace is blowing cold air instead of warm air, check the status of your household thermostat. If the thermostat isn’t on the correct settings, it could cause your HVAC system to circulate air that’s colder than you’re expecting. When you check, ensure the thermostat is set to “auto” rather than “on.” If the thermostat is set to “on,” the HVAC system will continue blowing air even when the furnace isn’t running, which will cause the air to be cold. However, if you switch this setting to “auto,” the fans and your heating unit will start running in unison. Checking the thermostat early on is a wise troubleshooting step that could save you quite a bit of time and a service call.

3. Pilot Light Issue

If you have a gas-burning furnace in your home, it relies on a pilot light to ignite the system’s burners. This process is how the heat generates to keep your home warm. If something prevents the pilot light from igniting, it’s likely to result in your furnace distributing cold air. For example, there could be an issue with the thermocouple, which regulates the amount of gas given to the burner. If you check your pilot light and don’t see a solid blue flame, you should schedule an appointment with our team at Brisk Air. Our technicians will take an in-depth look at your furnace’s combustion system and get to the bottom of the problem.

4. Clogged Condensate Lines

Modern HVAC systems have condensate drain lines to remove moisture from the system. These drain lines can gradually become packed with contaminants, leading to stubborn clogs. When this occurs, it can cause the furnace to shut off its burners. Suddenly, the air distributed around your home will be cold instead of hot. If you suspect your HVAC unit is having this issue, let our team members at Brisk Air inspect the system’s drainage system and clear out the blockage.

5. Leaking Air Ducts

Your furnace uses air ducts as pathways to circulate warm air to every corner of your home. Over time, your ductwork can become damaged or develop air leaks. When this occurs, significant amounts of the hot air can end up seeping out of the ducts while your heating system is operating. As a result, much of the air that does get blown into your living space may be cold or room temperature. Leaky ductwork can also cause many other problems that impact the comfort and efficiency of your household. For these reasons, it’s crucial to have your household air ducts professionally cleaned and inspected every two or three years. If your furnace is suddenly blowing cool air, you may need to schedule an inspection sooner.

At Brisk Air, we’re proud to provide residents of the greater Phoenix area with high-quality heating and air conditioning services. Whether you need system maintenance, repairs, installation, or replacement, our skilled technicians will get the job done promptly and for a fair price. Contact us at Brisk Air today to learn more about our services or schedule an appointment!

company icon