It’s a chilly winter night in Eastern North Carolina, and you have a furnace blowing out cold air. What’s wrong with this picture? The central heating system in your home is designed to provide safe, reliable warmth when you need it. If you find your furnace blowing out cold air, your heating system is failing to perform its essential function. Do you need to call a professional HVAC service, or is it something you might resolve yourself? Here’s a rundown of possible causes of your furnace blowing out cold air and what steps to take:
The setting for the thermostat fan is wrong.
If the fan setting for the thermostat is at “On” instead of “Auto,” the fan will circulate air continuously, even between heating cycles when the furnace is not producing hot air. During those times, you’ll feel cold air blowing out of the vents. The proper heating setting for your thermostat fan is “Auto,” which means that the fan stops circulating air when the furnace isn’t generating heat.
The thermostat-mode setting is wrong.
It’s a no-brainer, but it does happen: If the HVAC system is accidentally set to “Cool” instead of “Heat,” the air conditioner will be activated instead of the furnace. In that case, you’ll feel cold air coming from the vents.
There is insufficient air circulation.
If some factor such as a dirty air filter is obstructing air circulation through the system, the furnace may overheat. A safety sensor will shut down the furnace burner, and the unit will automatically continue circulating unheated air to cool system components. This is a job for a qualified HVAC technician to diagnose and repair.
The pilot light is out or the electronic igniter is defective.
If a gas furnace burner doesn’t ignite when the thermostat signals for heat, the system will blow cold air. Because a furnace pilot light or electronic igniter is a critical safety component, the furnace should be immediately turned off at the thermostat. Then, call for professional HVAC service immediately.
Stay comfortable and safe this winter. If a furnace blowing out cold air is an issue in your home, contact the professionals at Jackson & Sons for service immediately.