Why Exactly Is My Heater Blowing Cold Air?

Do you find yourself wondering “why is my heater blowing cold air?”

In the U.S., around 12.1 million homes have their own heating system. If you live in a cold area, the last thing you want when coming home is for your heater to blow out cold air.

Even with new units, there are still several heater problems that you can run into. Some are easier to fix than others. We’ve compiled a few common issues that could happen to help answer the question.

Thermostat Issues

The thermostat is one of the first things you need to check if your heater is producing cold air. If you live with someone else, it’s possible the settings got changed. You could have also turned the system to cool when trying to turn the fan on.

If you have a smart thermostat, you might have bumped the touch-screen display. This could change some of the settings or turn the temperature down without you knowing.

It’s also important to check that your thermostat isn’t set to “ON.” This will make your fan run without any heat. Make sure that it’s set on “AUTO” instead to have the heat back on.

Another important thing to check is if your thermostat’s compatible with your heater. If you changed it yourself without consulting a professional, you might have chosen the wrong model. Make sure to check work with a professional contractor for maximum efficiency.

Old thermostats could also need a new change of batteries. So make sure to examine your thermostat before contacting a professional for help.

Dirty Flame Sensor

The flame sensor is what determines whether your heater is producing any warm air. This is also what helps heat the air as it moves through the ducts. If your flame sensor is dirty, it won’t detect the temperature and blow out cold air.

To check for this issue, if your heater is blowing out cold air, try restarting it by turning your unit off then back on. As soon as the air starts blowing out, check if the air feels warm at first. If it switches to cold air right after, the problem may be with your flame sensor.

A dirty flame sensor means that your burner isn’t staying lit. This causes the air to come out cold after a bit. If this is the case, don’t try and change it yourself; it’s best to contact a professional heating repair company instead.

To clean or change your flame sensor requires opening up the burner. Attempting to do this yourself could cause damage to your unit if not done right.

Pilot Light Isn’t On

If you have an old boiler or gas furnace that isn’t blowing out cold air, make sure to check if the pilot light is on. The pilot light is a small gas flame used to ignite the burner and produce hot air.

This is a common furnace problem only faced by older models. You don’t have to worry about this with newer units as they will often have an electronic pilot light that won’t turn off.

A potential quick fix for this would be to reset your unit. First, you’ll want to turn off your furnace as well as the rest switch. Then, wait a few minutes and switch the reset back and turn the furnace on.

If the pilot light doesn’t turn back on or goes out after a while, you can try and light it yourself. To do this, make sure to check your heater instruction manual first. If you’re not comfortable doing it yourself, call on an HVAC professional to take a closer look.

Faulty Valve

If your pilot light still refuses to turn back on and won’t light at all, the problem could be with your gas valve. Your pilot light might not be getting any fuel to stay lit. If this is the case, your gas valve either needs to get cleaned from stuck dirt and debris or replaced.

Electronic Ignition Issues

As stated above, electronic models have ignition sources that don’t often go out. They can either be an intermittent pilot or a hot surface ignition. If you find your electronic heater’s ignition source not turning on, it’s not something that you can fix yourself.

You’ll have to get the failed parts of the system adjusted or replaced. This will require a visit to a repair technician or an HVAC expert near you.

Clogged Filter

Another probable cause for cold air blowing out of your heater is a clogged or dirty filter. When the air moves through the ducts and into the gas chamber, it passes through an air filter. Over time, dust and dirt could build up and clog it.

When this happens, it becomes harder for the air to pass through the gas chamber. This will cause the air not to get adequately heated as it comes out of the unit. It could also affect the quality of your indoor air.

Changing the air filter will fix the issue. Remember to get the right size and kind of filter.

Disconnected Utilities

Forgetting to pay your recent gas bill could be a reason for your heater not working. There could also be a problem with the gas line. These could be a cause for your utilities to disconnect, resulting in cold air coming out.

Contact your gas company and see if they can send over a technician to check your gas lines.

Why Is My Heater Blowing Cold Air?

You need not wonder “why is my heater blowing cold air?” anymore with this guide. It details how you can figure out the problem and tells you what you can do on your own to fix it. Don’t tolerate the cold air and get the problem fixed today!

Are you looking for professional heating and plumbing services? Some of the problems above need professional help to keep you out of accidents. Contact us today and we’ll help you out as soon as we can!