During a cold winter day, this is a very annoying problem to have. If your furnace or heating system all of the sudden starts blowing cold air through the vents, it’s a cause for concern and something you’ll want to address right away.
There are actually a few different reasons this might happen. We’ve outlined a few possible causes below. For a deeper diagnosis, however, you’ll want to give our professionals a call. Read on as we uncover why cold air might be coming from your furnace vents, and what can be done about it.
Sometimes your heating system problems aren’t with the actual heating system at all, but rather with the thermostat. If this component, considered the “brain” of your HVAC systems, is malfunctioning, it could be misreading indoor temperatures, or it might not be properly regulating the temperature in your furnace.
We suggest first checking your thermostat to check if it is set to “AUTO” rather than “ON.” If it is set to “ON,” then the fan will continue to blow, even if the heat exchangers of the furnace are not on. This means that room temperature air will come through the vents. It may seem chilly since the temperature of the air in the home will be lower considering how cold it is outside!
A Blocked Air Filter
A clogged-up air filter can cause considerable problems for both your heater and your air conditioner if you let it go unaddressed for too long. One of these problems is a lack of heat due to restricted airflow. A dirty air filter restricts the flow of air and can cause your heater to overheat.
When this occurs, your heater may shut down on its own as a safety feature. The fan will continue to run through as it cools down the heat exchanger.
Check on your air filter to see if it needs changing. If it does, change it out and see if that helps the problem. We also recommend that homeowners change their air filters every 1-3 months depending on the type of filter it is.
Broken Heating Elements
This applies to electric heaters. When any of the electrical components that are actually responsible for heating the air going through your furnace breaks, then you can of course expect cooler air to come through the vents.
Our professionals can inspect each heating element to pinpoint the source of the problem and repair it accordingly. Trust us, you want heating elements repaired as soon as possible to avoid potential safety hazards.
The problem with damaged ductwork is twofold. It allows contaminants and allergens in while letting heated air out into unoccupied spaces of your home like attics and crawlspaces. As a result, the heated air coming from your furnace may not actually reach all the rooms it’s meant to, and therefore you might feel low airflow or cool air coming from one or more of the vents.