Get In touch

icon-phone 24/7 780-448-0076

Why Your Furnace Is Blowing Cold Air?

Sep 16, 2015

Furnace Home Improvement
A service technician talking to a man while replacing a Lennox furnace filter installed by romaniuk heating in the basement.

Homeowners rely on their furnaces to keep them warm, in such instances, nothing is more frustrating than when your system is in working condition but blows cold air out of the vents. This is a big problem that be resolved as soon as possible, and the best way to troubleshoot tour furnace is to know some of the probable causes. Here we will be explaining some of the most common causes by finding out the probable reasons that why a furnace starts to blow cold air.

Why your furnace is blowing cold air?

  • Your thermostat is set to on. One very simple answer for your furnace blowing cold air is that the fan setting of your thermostat is set to “on” while it should be “auto”. The “on” setting means your furnace fan will keep running 24/7, irrespective of whether or not your system is in a heating cycle. It can be fixed by merely changing the setting to “auto” on your thermostat.
  • Your furnace is overheating. When your furnace overheats, it shuts its burners off but the fan keeps running in order to cool down the unit. So, may be you will get some warm air initially, but soon it will be replaced by cold air. Overheating is typically caused due to a dirty air filter. So, you can resolve the issue by replacing it with new filters. If filters are clean then contact your heating contractor in Edmonton.
  • Issues with safety devices and sensors. Furnace sensor and limit switch are two important components of a furnace. They control when your fan and burners turn on and off respectively. If any of these parts get dirty of start to malfunction, your furnace’s timing will get disturbed. The fan might turn on before your furnace gets really hot, or the burners might turn off in the middle of a heating cycle or the fan might never get the signal to turn off even when the heating cycle is complete. In any of these cases, your vents will throw cold air. Problems with these sensors and safety devices should be resolved by a professional.
  • You just turned on your furnace and if it blows cold air for some time, but soon that cold air is replaced by warm air then it is probably not a problem you should be worried about. When your furnace is in between heating cycles, the air that is present in the ducts cools down. In order for new warm air to pass through the ducts, the cold air needs to be cleared out. Once that cold air is pushed out, only warm air will be delivered to you.

If you have questions related to your furnace, or you would like a heating system installed, repaired or serviced in your home, contact Romaniuk, your heating contractors Edmonton.