5 Reasons Your Furnace Could Be Blowing Cold Air

You count on your furnace to keep you warm on those chilly days and nights. The last thing you want to experience is a drop in temperature and a furnace that only blows cold air. Yet it happens on occasion.

In some cases, the problem can be simple. In others, it may require servicing right away. To get you back on track, here are the most common reasons we see for that blast of cold air coming out of your registers, and what you should do to sort it out.

1. Timing. When you turn on your faucet, it takes a few seconds for hot water to arrive. It’s similar with your furnace. Warm air cools down as it sits in your ducts. When warm air is released from your furnace, it may push the cool air out through your registers before the warm air arrives. It doesn’t mean your furnace isn’t working, it’s a normal part of the process. This is especially notable with heat pumps.

2. Switching your fan to auto. In the summer months, your thermostat setting is “on” to allow continuous flow of conditioned air. When you transition to winter, turning it from “on” to “auto” will allow your fan to operate only when the furnace is running. If you miss this switch, it could be moving cooled air throughout the system when you’re furnace isn’t operating.

3. The pilot light is out. If your older furnace is blowing air, it could be a pilot light that is out. If you’re comfortable doing so, you can follow manufacturer’s guidelines to relight the pilot light. Most systems these days do not have a standing pilot and cannot be re-lit by any means a home owner has, if it does not lite please call and schedule an inspection with an HVAC technician.

4. The flame sensor is dirty. If you get warm air through the registers when the furnace first turns on, but then it quickly grows cold, it may be a flame sensor that is dirty. When the flame sensor is dirty, the gas burner won’t stay lit. An HVAC technician can service it and bring it back to working condition.

5. There’s a larger technical problem. Depending on the age of your furnace, a variety of things can go wrong. From simple repair work to installing a new system, the only way to find out where the issue lies is to call in a certified technician to investigate the problem. They can address everything from cleaning and regular maintenance, to replacing malfunctioning circuit boards, to replacing your entire system.

If your furnace is blowing cold air into your Marietta area home, we can assist you with your needs.