Why Is My Furnace Blowing Cold Air?

If the air flowing from the heat registers in your Texas home feels cool, take a few moments for some troubleshooting.

Ask yourself these questions:

• Did I inadvertently switch the furnace fan from auto to on?
• When did I last change the furnace filter?
• Is anything blocking the air registers?

Our qualified professionals at AiRCO Mechanical are here for you whenever you need help with repair, maintenance, or installation at your Round Rock home. We can recommend heating, ventilation, and air conditioning (HVAC) solutions for your comfort needs. 

We also can diagnose any potential problem with your heating and cooling system, but we recommend you consider your thermostat setting, furnace filter, and air registers before calling us. Your troubleshooting may uncover a problem you can fix. 

Why Look at the Thermostat?

If the thermostat setting is auto, the furnace blower fan will kick on when air is heated and distribute it throughout your home. Leave the setting to on, and the fan will continue operating even if the burners are off. As a result, it will circulate unheated air.

The simple, do-it-yourself fix is turning the setting to auto.

If you install a programmable or smart thermostat, you will not worry about incorrect settings again. A programmable thermostat with Wi-Fi capability will give you precise control of your comfort level. It will save on energy costs and allow you to take your thermostat controls with you via a smartphone app.

According to ENERGY STAR^®, homes with high heating and cooling bills, or those that are unoccupied most of the day, can save approximately $100 a year in energy costs with a certified smart thermostat.

Our expert technicians at AiRCO Mechanical can recommend a programmable thermostat that fits your lifestyle and budget. A programmable thermostat conveniently changes temperatures on schedule. You program the device and forget about it.

Check the Air Filter

An air filter clogged by dirt and debris restricts airflow to and from your furnace. Your furnace must work harder and longer to heat your Round Rock home. Safety components will shut off the burners if the furnace overheats, and the blower fan will circulate only cool air.

Remember to change your furnace filter every three months and inspect it monthly. 

What About Heat Registers?

Drapery, furniture, even seasonal decorations can restrict airflow to and from your furnace if they obstruct heat registers and air return vents. The restricted airflow may cause the furnace to overheat and the heating system to shut down.

Be sure to keep the space in front of air vents unobstructed. 

Other possible causes:

• If the condensate line in a high-efficiency furnace is blocked, a switch will activate to prevent water damage in your furnace by shutting the heater down. 
• A dirty flame sensor can trigger a burner shutdown. As a result, only cool air will circulate through the system. 
• Safety components will shut the heater down if the gas supply is weak. Check the gas valve to make sure it is open and supplying gas to the furnace. The lever of the valve should be parallel to the gas pipe. Inspect other gas appliances. Are they receiving an adequate supply of gas?
• Cracks and holes in air ducts can contribute to the cool air you feel exiting your heat vents. Damaged ductwork can allow cold air from unheated spaces, such as an attic, to enter ducts, while heated air escapes via those same holes and cracks. Our qualified technicians at AiRCO Mechanical can seal your ducts to prevent air loss. 

Call a Furnace Pro Today

The best way to avert furnace problems in your Round Rock, TX, home is with an annual inspection and cleaning. Our professionals at AiRCO Mechanical can have your heating system operating at peak efficiency in no time. Call us at 512.537.1234 or request service online.