What to Do When Your Furnace Blows Cold Air

The chilly months are upon us, and keeping cold air out of your home is essential to staying comfortable throughout the winter. Your furnace works consistently to keep your home feeling cozy and warm, and when the frigid air creeps in, your furnace is what keeps you heated.

On a cold winter day, you turn on the heat to discover your furnace blowing cold air into your living space instead of warm air. When it is -20℃ weather outside, you’d want your heating system to blow warm air, not cold. You may ask yourself, why is my vent blowing cold air? And what can I do about this? The first step is to troubleshoot your furnace.

Ignite Heating & Air Conditioning recommends Napoleon Home Comfort Systems.

How to Troubleshoot Your Furnace.

What Do I Do When My Furnace Is Running But Blowing Cold Air?

In most scenarios, the best solution is to call a professional and have HVAC technicians look at the issue. If a technician isn’t available to fix the problem immediately, a few simple checks can be looked at by yourself to ensure it’s working properly.

Ensure Your Furnace Is Turned On.

The classic advice of “is it turned on?” may seem redundant, but many situations could have caused your furnace to turn off without your knowledge. The number one cause for furnaces to turn off is if the breaker might have flipped. 

There are many reasons why this could occur. If you have recently had a furnace cleaner visit your home, or even a phone and internet technician making an installation, they may have unintentionally left your breaker off, as they typically will turn it off during an inspection and installation. It might also surprise you to know that we often hear of kids who have turned off the furnace switch by accident, not knowing what it is for. 

If you’ve had an electrical shortage, it can be typical for a breaker to flip without your knowledge. Or, in some cases, a breaker may be tripped but appears to be on. To fix this, turn the breaker off and on to ensure that the breaker is for sure on. If this is a regular occurrence, there may be other underlying issues, and checking with an electrician may be a good starting point.

What if your furnace is on and your breaker is fine? What next?

Ensure Your Thermostat Is Set to Heat.

Another quick and simple fix is to check your thermostat. Your furnace might be on and running, but the temperature will not get warmer if your thermostat setting is switched to “cool,” “off,” or “fan only.”

It’s a simple fix to get your heating cycle back up and running. If you cannot find this button on your thermostat, a thermostat manual will have instructions on where to find it and how to make the switch. Remember to check the batteries in your thermostat! Oftentimes, dead batteries in your thermostat will shut the furnace down.

If ensuring your thermostat settings are correct does not improve the situation, then checking the flame sensor or air filter is your next best option. 

Check the Flame Sensor.

The flame sensor is a built-in safety feature that all modern furnaces have. The flame sensor is designed to sit within the flame of the last burner on your furnace, farthest away from the ignitor. It’s purpose is to confirm that the ignitor did its job and has ignited the flames. Flame sensors get dirty over time and need to be cleaned off in order to get the signal back to the control board. If you haven’t had furnace maintenance completed in the last 5 years or more, a dirty flame sensor is a very common problem that could be avoided by regular maintenance.

If you are part of the Ignite Comfort Club, you would have had your flame sensor cleaned by an Ignite technician on the last maintenance visit. So, if you’re part of the Ignite Comfort Club, you can jump to the next step!

With so many furnaces available and so many different designs, it’s impossible for us to walk you through cleaning a flame sensor on this. If you are a handy person, check out our video on Instagram, that references how to clean a flame sensor. If you do not feel comfortable cleaning your flame sensor, don’t worry! Ignite is available here to help! Get in touch with our experts right away.

If your flame sensor is clean and your ignitor is igniting, the next step is to check your air filter.

Clogged Air Filters.

Air filters collect dust and debris that flow through your home. When your air filter fills with dirt, it can clog the airflow. Without consistent airflow, the heat exchanger may will over heat and automatically lock itself out. Clogged air filters could be the reason your heat is no longer working. 

It is essential to check your air filter roughly every thirty days to keep your furnace running efficiently. Replace your air filter if it is dirty, or clean your air filter if you have a reusable one. If you have any questions about replacing or finding your air filter, check out our helpful tips on air filter replacement. If your furnace filters are not clean, the furnace may have locked out. Most furnaces will lock themselves out for 1 hour after too many limit trips. Turn the power on and off to reset any error codes that maybe present.

If you find that your furnace is still blowing cold air after reading these tips, contact your local HVAC company, Ignite!

Furnace Repair and Maintenance in Edmonton and Sherwood Park.

At Ignite Heating, we have 24/7 heat emergency service because your home comfort is our top priority. If your furnace is not keeping you warm this winter, contact us today for any of your HVAC needs.