Is Your Furnace Blowing Cold Air? Don't Panic

by Greg Leisgang on February 24, 2014

Posted in: Furnaces

There is nothing more frustrating than a furnace blowing cold air, but there's no need to panic. There are a few things you can troubleshoot on your own before you call the HVAC professionals.

The following are typical issues that cause a furnace to blow cold air.

  1. furnace blowing cold airWarm up period. It is typical for cool air to emerge from the vents at first because it takes a minute or two to for the furnace to warm up. If the air still feels cold after two or three minutes of air flow, it's time to start looking for the cause.
  2. Thermostat settings. Sometimes the thermostat settings are accidentally knocked from "auto" to "on". If this happens, the system will continue to circulate and blow air through they system, even when the furnace's heating element isn't on. Make sure your thermostat is set to "auto". The next step is to check your thermostat settings to make sure the temperature hasn't been readjusted unintentionally.
  3. The pilot light is out. If you have a gas furnace, there is a chance the pilot light has gone out. If you have lit it before, or feel comfortable following the manufacturer's instructions, you may be able to re-light it yourself. If you do not feel comfortable doing this, then don't! It can be very dangerous if you aren't sure what you are doing. In addition to the fire risk, leaking gas can lead to carbon monoxide poisoning. You can call your local utility company or an HVAC contractor to make sure it is lit safely.
  4. Dirty flame sensor. If you scheduled a routine furnace inspection and tune-up, your flame sensor should have been cleaned. However, over time, dirt and rust build-up will prevent the flame sensor from working properly. This should be taken care of by a licensed HVAC technician.

If none of these issues is the cause, odds are you have a more technical problem that will need to be diagnosed and repaired by professionals.

Is your furnace blowing cold air? Contact Tri-County Heating & Cooling and we'll get your house warmed up again.

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