A common question we hear from homeowners experiencing problems with their furnace, “Why is my furnace blowing cold air?” Well, the answer could be simple, or may require the attention of a certified HVAC professional. With the winter months quickly approaching, it can be very frustrating having your furnace not work during the winter.  Here are a four of the most common reasons your furnace would be blowing cold air:


  1. When a furnace first starts up the fan will often start to blow cold air before it has a chance to heat up. This cold air is normal before the furnace fully kicks in. Depending on how long it’s been since you’ve last used your furnace, this could last anywhere from a few seconds to a few minutes.


  1. If it’s been a few minutes since and your furnace is still blowing cold air, you next step would be to check your thermostat. One common mistake that people make is having their thermostat set to “fan” instead of “on” or “auto.” This causes your fan to blow air without actually prompting the furnace to heat the air. Check your thermostat settings before you start worrying whether or not your furnace is broken.


  1. The most common cause for your furnace to be blowing cold air is a dirty flame sensor. If your sensor has become overly dirty you furnace will turn on and begin heating, but quickly cool down. The best way to prevent this is to get regular maintenance on your furnace or have a professional HVAC technician clean your flame sensor.


  1. Another reason that a furnace fails to heat the air is that the pilot light has gone out. Your furnace should include fairly simple instructions on how to re-light the pilot. If the pilot light continues to go out after being re-lit, contact a professional for assistance, as there is a potential for danger when dealing with natural gas,


For more information on furnace maintenance or to schedule an appointment contact Builders Choice Air Systems in London, Ontario and take advantage of our affordable furnace tune-up. Click here to Book Now!