Why Is My Furnace Blowing Cold Air?

Winter in Amarillo, TX, can dip into the teens or even lower, so having a furnace that works reliably is crucial during this frigid time of year. If your furnace is blowing cold air, it’s important to understand why it’s happening and what you can do about it. The team at Amarillo Air Conditioning has helpful tips explaining why your furnace might be blowing cold air, what to do if your electric furnace isn’t blowing hot air, and more. 

What Causes a Furnace To Blow Cold Air?

If your furnace or heater is blowing cold air, it may happen for several reasons. Some of the most common causes include improper installation, one or more dirty or blocked components, or air filter issues. No matter the cause, it’s important to know how to find and diagnose the issue and when you should hire the professionals at Amarillo Air for expert heating repair. 

Common Reasons Your Furnace Is Blowing Cold Air 

There are several common reasons why your furnace might be blowing cold air. Here are some of the issues homeowners often face when they realize their furnace is not blowing hot air.

Air filter issues

A dirty or blocked air filter restricts airflow. This ultimately prevents your furnace from heating the indoor air properly. It also causes your system to work harder, resulting in less energy efficiency and higher energy bills. 

Problems with the pilot light

If you have a gas furnace, cold air could be blowing because the pilot light is out and can’t heat the fuel properly. It may also be because the pilot light is damaged or dirty, or you may need to adjust the reset toggle. However, if you notice the odor of gas or if your pilot light has a yellow or orange flame instead of blue, turn off your furnace and contact a professional HVAC technician right away. 

Damaged heat exchanger

A cracked or damaged heat exchanger can cause a gas leak. Not only is this dangerous due to the possible release of toxic carbon monoxide into your home, but it can prevent heat transfer to the air. If you suspect this is the issue, it’s best to call Amarillo Air so we can troubleshoot the problem.

Clogged condensate lines

Newer furnaces use condensate drain lines to help remove excess moisture (condensation). However, if the line is blocked, it can deactivate the burners and cause your furnace to blow cold air. Any blockage of the condensate lines will eventually cause your furnace to malfunction.

Thermostat issues

If your furnace is blowing cold air, it could be due to a malfunctioning thermostat that requires calibration, repair, or replacement. In some cases, the fan could be set to “off” accidentally. If the thermostat is set to “auto,” cold air may also blow from the furnace. 

Gas supply issues

Cold air could be blowing from your furnace because you have an issue with the gas supply line going into your home. The furnace is designed to automatically turn off if it doesn’t receive enough gas to heat the air. Low gas pressure or a faulty gas valve could be the culprit, so it’s best to contact the pros at Amarillo Air to address the issue. 

Faulty limit switch

A faulty limit switch can activate the furnace’s blower fan before it has warmed the air adequately. When this switch can’t accurately detect the indoor air temperature, the fan may push cold air through your ductwork and vents. This issue may also result in short-cycling or cause your furnace to run constantly, even when the air reaches the optimum temperature. 

Blocked vents

If the air vents in your home are blocked or obstructed, warm air can’t properly circulate or blow into your home. Make sure your vents are free of obstructions like furniture, area rugs, or other objects. This is also a good time to clean your vents if they’re dirty to improve airflow.

Why Is My Heater Blowing Cold Air After It First Turns On?

It’s normal for your heater or furnace to blow some cold air when you first turn it on. However, the air should warm up fairly quickly if everything is working as it should. If your heater continues to blow cold air after it’s been turned on and left on for several minutes or more, it could be due to one of the reasons listed above. 

Can a Furnace Blow Cold Air if It’s Overheating?

Yes, a furnace can still blow cold air if it’s overheating. This is because a safety mechanism inside the furnace shuts off the heating element once it reaches a certain temperature. That mechanism causes the fan to keep running and blowing cool air instead of hot air to protect the unit from further damage. This is usually caused by restricted airflow due to a dirty air filter.

What To Do When Your Electric Furnace Is Not Blowing Hot Air?

If your electric furnace isn’t blowing hot air, consider these tips to help you troubleshoot and correct the issue:

• Confirm that your thermostat is set to “heat” and the desired temperature.
• Inspect the air filter and replace it if it’s dirty or clogged.
• Check your home’s electrical panel and find the circuit breaker for your furnace to ensure it hasn’t tripped. You may just need to flip the breaker to get it to work again. 
• Listen carefully for unusual noises coming from the blower motor to ensure it works properly.
• Inspect the condensate line and look for clogs or blockages that could be causing your electric furnace to blow cold air.
• Make sure the air ducts in your home are clean and free of cracks or other damage.
• Look for loose wiring connections at the furnace or thermostat.
• Schedule regular preventative maintenance, including inspections and tune-ups, to prevent furnace issues.

Contact Amarillo Air Today!

If your furnace is blowing cold air, don’t leave things to chance. The professional team at Amarillo Air Conditioning provides expert repairs, a comprehensive Home Comfort Club maintenance plan, and more to keep your Amarillo home warm and comfortable all winter. If you need furnace repair or want to schedule another service with us, contact us today!