When you turn on your furnace, you expect it to run smoothly and quietly, but sometimes that’s just not the case. Trying to figure out why your furnace is bowing cold air can be very frustrating. Fortunately, there are some quick ways you can assess the problem and determine if it’s something you can fix yourself or if it’s time to call an HVAC professional.

Thermostat Issues

If your furnace is blowing cold air and the thermostat is set to heating mode, it may be an issue with the thermostat itself. Check that the thermostat is in fact turned on and not set to auto. If you’re still having trouble, it could be time to replace your old device with a newer model that has a more efficient interface.

Pilot Light Issue

A furnace’s main source of heat is a small flame called the pilot light. This flame burns continuously and heats up the gas that powers your furnace. If your pilot light is out and you can’t get it re-lit, there could be a problem with your thermostat or perhaps you’ll need to replace the pilot light all together. You should also check to make sure that all of your vents are clear so that air can flow freely through them and into your home.

Dirty Air Filter

If you are having trouble getting warm air from your furnace, one of the most likely culprit is a dirty or clogged air filter. If your filter is dirty or has been neglected for too long, it can cause cold air from your furnace to blow into your home. To see whether this is the case, check and replace or clean out the filter if necessary. If replacing/cleaning out and reinstalling does not work, there may be something wrong with your system that requires professional attention.

Leaking Air Ducts

Leaking air ducts can cause a variety of problems, the most common of which is that your home’s furnace will have to work harder (and use more energy) to keep your house warm. The loss of heat from leaking air ducts also makes it more likely that you’ll feel cold inside your home.If you find yourself experiencing both of these issues at once—cold air blowing out through your vents and an inability for your furnace to keep up with heating demands—then it may be time to have the air ducts in your home checked for leaks.

Blocked Condensate Line

If you’re feeling cold air blowing out of your furnace when it should be heating, it is possible the issue is a blocked condensate line. Some furnaces like air conditioners have condensation lines. Condensation from your hot water heater or humidifier is being blown into the air. Your furnace may also be making an unusual noise, such as a buzzing or clicking sound.

If you’ve tried everything and your furnace is still blowing cold air, call a professional. A trained technician can help pinpoint the problem and fix it quickly. He or she will also be able to troubleshoot any issues that may arise in the future, which means you’ll save yourself time and money in the long run.