Why is My Furnace Blowing Cold Air?

When you turn on the heat to keep your family warm in these cold Sudbury, Ontario winters you expect that your furnace will push hot air through your system and warm up your home. But what happens if your vents have only cold air coming from them. Here are a few reasons that might explain why this is happening.


The Fan Is Off 

If you are finding that your system is only producing cold air, check your thermostat. If you keep your fan off during the summer months you need to make sure you set your fan to “auto” nowe that it is cold. This will ensure the fan is pushing warm air when the furnace is on.

Extinguished Pilot Light

If you have an older furnace your pilot light might have gone out. New furnaces tend to have electronic pilot lights that can’t go out but if your unit is over 10 years old then you might want to have the pilot light checked. If you are unsure how to find or light your pilot light safely then contact a professional to come and take care of this for you.

Dirty Flame Sensor

You may not have heard of a flame sensor but it is an important part of your furnace. This sensor determines if the burner is producing heat and helps with heating the air as it moves through the HVAC system. If you find that cold air is blowing out of your vents try turning the unit off and on. If when you turn it back on the air is warm for a minute and then changes to cold air you might have a dirty flame sensor. Do not try to clean this yourself. This is a job for a professional HVAC technician to ensure it is done safely and without causing damage to your unit.

Clogged Filter

If your filter is dirty or clogged you might find that your furnace is blowing cold air. This is because the air cannot move through the system as easily causing the air to not become heated fully as it moves through to your vents. This can be solved by changing your dirty filter to a clean one, but make sure to check the filter’s size before you change it. If you are unsure how to do this you can always contact a professional to come and do this for you.

Thermostat Changes

The very first thing you should check is your thermostat. If someone accidently changed the settings then you might find that your thermostat is set to cold instead of heat. This will cause cold air to blow out of your vents instead of warm air. If your thermostat is the culprit then simply changing it back to heat will fix the issue and save you having to call a professional.

Disconnected Utilities

If there is a bill that was forgotten, or a problem with your gas line then your utility company might have to turn off your gas. This will result in a lack of warm air coming from your vents. Try calling the gas company to make sure your account is in good standing and that there are not infractions on your gas line that have caused the supply to be cut off.

If you are having issues and need a professional in the Greater Sudbury Area, Northern Climate is available to help you. Contact us today at 705-586-4300 or book online.