Why is My Heater Blowing Cold Air?

Updated: April 9, 2024

There is nothing more frustrating than coming in from a cold winter Texas day to find that your heater is blowing out cold air. You’re expecting to come in and get toasty only to find that is colder in your house than being outside! There are several reasons that this issue could be happening to your heating unit.

In order to understand why a heating unit is malfunctioning, it’s important to understand how the system works. There are four main components to a heating system. These include the ductwork, fan, burners and fuel system. If any of these are experiencing a problem, your furnace will most likely begin malfunctioning. Below are some possible issues that could be causing your problem.

• Low fuel. Fuel is the heat source for every furnace, and if there is no fuel being supplied, you will have cold air blowing on you.
• Dirty filter. Always change the heater’s air filter when troubleshooting. A clogged filter can block airflow.
• Clogged hose. Burners will not light if you have a clogged condensate hose. The fan may still be blowing, but the burner will not light.
• Damaged ductwork. Cold air will get into your system if there are any holes or tears in your ductwork. Despite its name, duct tape is not recommended for sealing these holes.
• Worn parts. A bad gas valve, a burned out thermocouple or a faulty electronic switch that can cause a furnace to malfunction. These types of issues should be handled by an experienced technician.
• Obstructed burner. The burner itself can actually get clogged with debris and dirt and should be checked as well.

Sometimes a quick reboot of your heating system can actually solve the problem. Switching the main furnace switch off, waiting 30 seconds and then turning it back on can allow fuel to flow back to the burner.

For more detailed information on troubleshooting your heating and cooling system, read: Troubleshooting 6 Common AC/Heat Problems. However, if your furnace is affected by any of the issues above, it’s important to call an HVAC technician to check it out. Call Richmond’s Air to talk to one of our certified HVAC technicians. We can help get you warm and comfortable for the winter!