Why is My Furnace Blowing Cold Air?

Your home’s heating system is designed to keep you warm during cold winter months. So when you turn it on, the last thing you expect is for cold air to start blowing out. If your furnace is functioning more like an air conditioner, you must consider multiple factors.

Thermostat furnace settings

The thermostat is one of the first places to look when faced with any HVAC problem. Thermostats have many settings, but AUTO and ON are what you’re concerned with. If your thermostat is set to ON, the fan that moves air from the furnace will run non-stop. This can cause a problem when it’s not actually providing heat. Switch to AUTO so the fan will only circulate air that has been warmed by the furnace.

Furnace pilot light blown out in Salisbury, NC

If your furnace is gas-operated, it uses a pilot light as an ignition. When this flame gets blown out, the unit stops producing heat. Try relighting the pilot light; if it won’t start, there is an interruption in your natural gas supply. Also, make sure that the supply valve is turned to on, and check to see if other gas-fueled appliances in your home are functioning properly. Gas companies sometimes have to do maintenance and repairs which can shut off the supply temporarily as well.

Beaver Brothers furnace cleaning

Proper HVAC maintenance includes routine cleaning. Dirty furnaces are practically guaranteed to work poorly. This includes the filter, which must be cleaned or replaced regularly. Ductwork also plays a role. The accumulation of dust and debris can block the airflow through your duct system, potentially damaging it. Holes and tears in ducts allow cold air to come from the attic or crawlspace and into your home.


A heating system that doesn’t provide heat is a serious problem. Call Beaver Brothers, Inc. for HVAC inspection in Salisbury today!