The purpose of your furnace is to provide hot air to keep your home warm during the colder months. There’s something obviously wrong if it starts to blow cold air. While some problems are easily fixable, others are red flags that need to be addressed quickly. Find out more about why your furnace is blowing cold air, and what you need to do about it.
Problems With Your Thermostat
A problem with your thermostat may be as simple as it not being set at the right temperature or as complex as a complete malfunction. In the first case, you can set the thermostat to the right temperature or reset it to auto mode. You might also put the fan on the auto setting. This will turn the fan off when your furnace isn’t heating your home, then turn it back on when heating is needed. If the thermostat is broken, you’ll need to call in an HVAC professional to fix or replace it.
The Furnace’s Fan Limit Switch Is Broken
Your furnace blowing cool air may mean that the fan limit switch isn’t working. This component takes the temperature of the air inside the furnace and controls how the blower works. If this switch isn’t working, your furnace’s blower may work continuously even when it’s not heating.
The result is cool air being blown through your home. In some cases, your furnace may shut down altogether. Problems with the fan limit switch might stem, like so many other HVAC problems, from a dirty filter. It’s good practice to make sure the filter is changed regularly or kept clean.
A Broken Flame Sensor
Another reason the furnace might be blowing cool air is a malfunctioning flame sensor. As its name says, this component is supposed to sense the flame. If there’s no flame, a properly working sensor shuts the furnace down if the gas is on. If the sensor is broken, it will still shut down the furnace because it can’t detect the flame.
Leaky Ductwork
Leaky ductwork may also cause your furnace to blow cool air because the warm air is escaping out of it. If your ductwork is visible in your basement or crawlspace, you can put your hand near your ducts and feel warm air coming out of them. Compromised ducts not only prevent warm air from getting to you, but they also raise your energy bills.
Call Us for Furnace Problems
A furnace that’s blowing cold air may be a sign that something’s seriously wrong. For expert furnace repair, don’t hesitate to get in touch with our HVAC professionals at Absolute Electrical Heating and Air of Denver, CO.