Why is My Furnace Blowing Cold Air

A cold breeze inside your house may be startling. Before you blame the furnace, make sure that it’s not a draft that escaped your attention during your fall preparations for winter. Additionally, verify whether the cold air is coming from the vents and whether the furnace blower is actually running. Leaky ducts could be contributing to the infiltration of cold air, especially if a north wind has cropped up. When you are certain that your furnace is responsible for moving cold air into various rooms, it is time to investigate further.

Start-Up Issues

At the height of the heating season, your furnace may cycle on and off constantly, keeping the air in your home relatively warm. As seasonal changes take place and your heating needs decrease, you may have long periods of no heating. Some homeowners even shut their furnaces off during the day. Restarting your unit will include a short period of cool air movement as the air in the ducts is blown out. Hot air will usually blow within a few minutes.

If you this isn’t your situation, you may need to do some troubleshooting to eliminate simple explanations:

• Check your thermostat – settings may have been changed inadvertently, and you need to verify that your unit is issuing a call for heat. Another family member may have adjusted the buttons to cooling. Verify that batteries for the unit are good as well.
• Check your utilities – verify that the gas supply for your house hasn’t been interrupted. Try turning on a stove burner for a quick result. Check your fuse box and electrical connections for the furnace as well. You may have a tripped switch that simply needs to be turned on again.
• Check the condition of your air filter – a dirty filter can cause many types of problems. Make a replacement if your existing filter is filthy.
• Check the pilot light – if your pilot is out, you won’t get hot air. If it won’t relight, you may need assistance from your heating contractor.

Additional Possibilities

Overheating can sometimes trigger problems in a furnace as well, causing it to stop heating until the equipment cools. If your unit has been running consistently, you may want to shut it off for 30 minutes to allow a cooling period. Try operating it again, and provide another 30-minute cooling period if needed. You can also check your system for a reset button. If there isn’t a reset, you can do a manual reset by dropping your thermostat settings, shutting off power to the unit at the fuse box and allowing a five-minute wait period. Turn the power back on, and raise the heat setting to initiate a call for heat.

Call for Heating Services

If you’ve exhausted these measures, it’s time to consult with your heating repair expert, Brennan’s Heating & Air Conditioning. Our Arlington, VA, office can schedule a service call at your convenience, and we offer 24-hour emergency service for urgent heating repair needs.