Why Is My Furnace Blowing Cool Air?

Is your furnace blowing cool air instead of hot air? Figuring out why your furnace is blowing cool air can be challenging, especially if you don’t know exactly how a furnace works. Fortunately, Quick Serve Pro is here to help you figure out why your furnace is blowing cold air and advise you on whether you can address the issue yourself or call a professional HVAC technician for a furnace service New Jersey. Continue reading to find out why your furnace is blowing cold air instead of warm air.

Thermostat Configuration

If your furnace is blowing cold air, the first thing that you should check is your thermostat, which controls both the temperature and the furnace fan. The fan setting on the thermostat may be set to “on” instead of “auto.” When the fan setting is set to “on,” the fan will constantly blow air even when the heat is turned off, producing cold air. Luckily, this is an easy fix; simply change the fan setting to “auto” so the fan only blows when the heat is on.If the fan setting isn’t the issue, check the thermostat settings next to make sure that they are correct. It's possible that another member of your family adjusted the temperature!Another possibility is that the batteries in your thermostat are running low. While some thermostats are connected to the home’s electrical system, many thermostats rely on batteries that must be replaced. These batteries only need to be changed occasionally, so if you recently installed a new thermostat, you should not be experiencing this problem. If you are having issues with a new thermostat that you installed by yourself, you may have wired it incorrectly or it may not be compatible with your HVAC system. We recommend calling an HVAC specialist for furnace service New Jersey since you don’t want to risk damaging your thermostat.

Clogged or Dirty Filter

Furnaces contain filters that trap dust, dirt, and particles before they can be blown throughout your home. However, these filters need to be replaced every 1-3 months or they can become clogged and cause the furnace to overheat. When a furnace overheats, it cools itself down by blowing cool air, which causes cool air to blow out of the ducts. Simply replace the dirty filter with a new compatible filter to resolve this issue. Then restart the system and check the vents after a few minutes (after all of the cold air has blown out of the ducts) to confirm that it’s blowing hot air. We recommend changing your filter every 1-3 months to prevent your furnace from overheating again. Be sure to set a monthly reminder so you don’t forget!

Malfunctioning High Limit Switch

If the furnace overheats several times as a result of dirty or clogged filters and the problem isn’t resolved, the high limit switch can fail. When this occurs, the fan will turn on to cool the overheating furnace down. If the high limit switch breaks, you’ll need to call an HVAC specialist to replace the high limit switch, although you can still replace the dirty filter on your own.

Clogged Condensate Line

The condensate line is used to remove water from the condensing unit, but like all other parts of a furnace, is susceptible to wear and tear. Condensate lines can become clogged and activate a switch, preventing the burners from igniting and causing cool air to blow throughout your home. Fortunately, most HVAC companies have specialized tools that can clear the line. After clearing the line, your HVAC specialist will reset the system to get it back up and running. To prevent the condensate line from becoming clogged again, we recommend hiring a reputable HVAC company for regular maintenance. They will ensure that your HVAC system and its many components are in good working order and if necessary, will make repairs.

Low Fuel or No Access to Fuel

Furnaces run on fuel, which can be oil, gas, or electricity depending on the type of furnace you have. In order to run an oil furnace, there must be enough oil to produce heat, so check the tank to determine if it's empty or low. Similarly, a gas furnace is not able to generate heat unless the gas valve is open. Make sure to regularly check your gas valve to ensure that it hasn't seized and to avoid more complicated issues down the line. If you have an electric furnace, it will not blow cold air if it isn’t receiving power, because the fan requires energy to function; however, it won’t work. If your electric furnace isn’t working, confirm that it is turned on, and if so, check for a blown fuse or breaker.

Leaky Ducts

Many homeowners overlook their ductwork, yet leaky ducts can cause your furnace to blow cold air. The ductwork carries warm air to different rooms in your home; unfortunately, ducts are prone to leaks. The problem with leaky ducts is that they not only let warm air escape but allow cold air that is around the ducts to enter and circulate throughout your home. Call a reputable HVAC technician for a furnace service New Jersey. They will examine your ducts and repair any leaks that have occurred as a result of an unhooked duct, existing leaks reopening, or fractured ducts that weren’t screwed together correctly.

When Should You Call a Professional

Most of the issues listed above should be handled by a professional HVAC company for furnace service New Jersey since they have the necessary experience and tools. However, you’re welcome to tackle basic maintenance on your own such as changing the furnace filter, checking the valves, and adjusting the thermostat. If your furnace is blowing cold air, give Quick Serve Pro a call. We’ll send one of our experienced technicians over to repair your furnace as quickly as possible!

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