Why Is My Heater Blowing Cold Air?

Winters in Humble don’t usually get too cold, but there is comfort in knowing you can heat your home when you need it. When you feel cold air blowing from your vents instead of warm air as the temperatures start to drop outside, don’t panic!

Keep reading to learn more about what may be causing your heater to blow cold air during winter, and call Air Tech of Humble, your local experts in heater repair and heater replacement.

Check Your Thermostat

As the seasons change, weather conditions can have dramatic mood swings. Thermostats allow control over the conditions in your home, so make sure yours is set correctly. Keeping up with what front blows your way is tricky, especially in Texas, where it seems to change every week!

Switch your thermostat from ‘Cool’ to ‘Heat,’ and set the fan to ‘Auto.’ When the fan is ‘On’ while heating, it will blow air even if the furnace isn’t running. This means cool air will come through your vents.

If the above settings don’t work, you may have a different thermostat problem. In battery-powered models, ensure the batteries are not weak or dead. There may even be an issue with the wiring, especially in an old unit. New thermostats installed incorrectly or that are not compatible with your heating system can also blow cold air.

Your Furnace Needs To Warm Up

When you turn the hot water knob for your shower, it takes time for warm water to reach the shower head. Well, your furnace works similarly. Meaning, the cold air in your ducts will blow out before hot air reaches the vents. If the air still feels cold after 15 minutes, there may be another problem with your system.

Your Furnace’s Filter Is Dirty

Air filters collect dust and other debris from your home’s air supply. They need changing at least once every 90 days, depending on the number of people or pets in your home. A dirty, or clogged, filter will restrict the airflow to your heater. This causes it to overheat and shut down to prevent a fire or other damage.

A visual inspection can help you decide if the filter is dirty, just be sure to turn the furnace off before checking or removing the filter. Most hardware or home stores carry affordable filters, so if it seems dirty, replace it.

Clogged Condensate Line

Newer, high-efficiency furnaces are equipped with condensate lines to transport water from the unit. A blockage in the condensate line will trigger a kill switch to prevent water damage. This prevents the burner from igniting and will cause cold air to blow through your vents.

Look For a Tripped Breaker

When the breaker supplying electricity to your heater trips, heat won’t circulate throughout your home. Electric furnaces may not start at all when the breaker trips. Newer gas furnaces often have an electric starter to ignite the burner, so a tripped breaker won’t prevent it from starting, but will prevent it from heating air.

If you find a tripped breaker, reset it.

The Pilot Light is Out

The pilot light is a small, blue flame used to supply heat to gas furnaces. Newer models (less than 20 years old) have electric pilots that are only on when needed, as opposed to older gas units that have one constantly lit. The flame may go out due to an issue with your gas supply or if the pilot breaks.

If your pilot light is out or won’t stay lit, your unit may blow cold air.

Your System Has Overheated

Furnaces are programmed with a safety feature that will shut the system down when it overheats. This function may sound bad, but it is actually a good thing and doesn’t signal a broken unit. It can prevent carbon monoxide leaks, fires, or even an explosion.

Your system can overheat due to a mechanical failure, dirt buildup (due to a clogged filter), or simply because of age, as its performance declines.

Damaged Ductwork

Your home’s HVAC system relies on the ductwork to function efficiently and send air throughout your home, year-round. If your unit is operating properly but you feel the wrong air temperature coming from the vents, leaky or damaged ductwork may be the problem.

Any holes, leaks, or disconnections in your air ducts are openings that will allow warm air to escape into your attic, before it reaches your vents, and push cold air from there into your home. These leaks may be due to damage from small animals, such as mice or rats, or degradation over time as it ages.

Ductwork leaks should be sealed, or replaced, as soon as possible.

Contact Air Tech of Humble

Adjusting thermostat settings, replacing a furnace filter, and resetting a tripped breaker are all safe things for homeowners to try when troubleshooting heater problems. If you have questions, need assistance or if your furnace is still blowing cold air after checking those things, our technicians can help.

Air Tech of Humble is prepared to diagnose your heating problems and fix them, seven days a week with a 100% satisfaction guarantee. We can make repairs in the Houston, TX area almost immediately, and provide personalized solutions to make your home comfortable again.