Don’t immediately panic if your residential furnace is blowing cold air. The solution could be as simple as changing a setting on your thermostat. Our furnace contractors in want to help you better understand the heating system in your home so you can save time and money. Continue reading to learn why your gas or oil furnace is blowing cold air and how to plan your next steps.
Why is my furnace blowing cold air?
- Thermostat is set to “ON” instead of “AUTO”
- Furnace overheated
- Air filters are dirty and need replacing
- Pilot light is out
Thermostat is Set to “ON” Instead of “AUTO”
Before calling our heating and cooling company, make sure your thermostat is set to “AUTO” and not “ON”. This will be the first thing our furnace contractors in Lansing, MI check. Your residential furnace is designed to kick on once the temperature inside your home drops below the programmed temperature setting. When the thermostat is programmed to “AUTO”, this means the furnace blower will only push air through the vents when the burners are on.
If the thermostat is set to “ON”, the furnace blower will constantly push air through the vents, regardless of whether it’s heated or not. Changing this setting yourself is simple and can save you the cost of having one of our furnace contractors come out to your home.
You’ll know your residential furnace has overheated if you notice it blowing hot air, then cold air, before stopping completely. As a safety precaution, your furnace will automatically shut off the burners and continue running air to cool down the unit. Your furnace completely shuts off once it has reached a safe temperature.
A common reason why residential furnaces overheat is dirty air filters, which block airflow and cause your furnace to work harder to produce the same amount of heated air. If you recognize the signs of an overheated furnace, call our heating and cooling company as soon as possible. A dirty air filter is easy and inexpensive to replace compared to having to repair the heat exchanger. Check out our blog post to learn more about the importance of furnace maintenance.
Pilot Light is Out
The pilot light is responsible for igniting the gas in your residential furnace and heating air. However, if the pilot light is out, your furnace will only be able to blow cold air. Each furnace is a little bit different for how to light the pilot. Be sure to check with the manufacturer’s instructions before attempting to light a gas furnace.
If the pilot light refuses to stay lit, you’ll need to call one of our furnace contractors to fix any issues with the thermocouple. While minor issues can be handled by experienced homeowners, you should always call us for any outside your comfort zone. If you suspect something more serious is wrong with your residential furnace, check out our blog post on the 5 signs you need furnace replacement.