Why Is My Furnace Blowing Cold Air?

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Imagine it is a cold Texas winter day. You’ve driven home through crazy traffic and finally settle down to relax . . . and your heater starts blowing cold air! This could be a prime time to panic, but don’t. Here are a few things you can check to troubleshoot your system before calling Arise to help.

Check your Thermostat

Make sure your thermostat is set to the correct setting. Check the ON/AUTO switch. If it is set to “ON” the blower will run constantly, even when the furnace isn’t heating any air. The air that comes through the vents will seem cold because it is room temperature air. Turn your thermostat to “AUTO” so the fan will only run when the furnace is heating and you won’t get tepid or room temperature air.

Change the Air Filter

A dirty air filter will cause your furnace to overheat by restricting the air flow in and out of your furnace. If it does overheat, the safety control will shut off the burners causing the fan to blow cool air versus heated air through the house.

Check the Pilot Light

If you have an older furnace with a standing pilot, the pilot may have gone out, causing the furnace to not heat. It is a simple fix – just relight the pilot. If it continues to go out after you relight it once or twice, it is indicative of a bigger problem that is potentially dangerous. Call us at 512-267-5000 or request service online.

Reboot Your System

If you have a newer furnace, it probably is controlled by electronic components. Sometimes there is simply a glitch in the system and it needs a simple reset, the same way you would restart your computer or phone. If you turn off your furnace breaker or power switch for 30 seconds and then back on, it may reset itself and begin functioning correctly. If it doesn’t start working the way it should after you have restarted it, call Arise or request service online today.


The older your ductwork, the more likely it is to be damaged or leaky. A damaged or leaky duct can allow un-heated attic air into your home or allow the heated air to escape into the attic before it arrives at its intended register (grille). You may do a quick inspection of the ductwork yourself, but it is possible that you may not be able to visually detect rips, tears or leaks that are causing issues. Arise can perform a detailed duct system inspection. Call us or request service online.

Is Your Furnace Short-Cycling?

Does your furnace begin blowing then quickly shut off without reaching the thermostat set temperature? This typically indicates a failure in one of the furnace’s safety components that will require service by a trained technician. Call Arise and we will send an HVAC service technician out quickly to get your furnace working again.

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Call us at 512-267-5000!

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