It’s the middle of winter and you’re trying to warm up. You check to make sure all the windows are closed, there are no drafts or cracks allowing cold air to escape in. It’s still cold in your home. What’s the issue then? The most probable cause is that your furnace isn’t blowing out hot enough air–causing your home to be chilly. Here are a few reasons your furnace isn’t blowing out hot air.
Your Furnace Thermostat
This is a more common issue; many homeowners have their thermostat fan setting to “on” rather than “auto.” Keeping the thermostat fan “on” will allow the fan to continuously run without providing heat.
Furnace Pilot Light
If your furnace is older and has a continuous pilot light, then the pilot light may have gone out. It could’ve gone out from something as simple as a gust of air. If you feel comfortable, relight the pilot light (instructions are usually on the furnace) if not, call an HVAC professional.
Does your furnace have an ignition system? The problem for cold air blowing out could be an issue with the ignition system. This means the furnace isn’t lighting the fuel and it won’t heat your home. Ignition systems usually need to be replaced by a certified technician to ensure it’s being installed correctly.
Damaged ductwork is another cause of cold air blowing into your home. Holes, cracked or broken ductwork can cause the crisp air to leak into the ductwork causing your home to feel cooler.
Dirty Furnace Filters
When troubleshooting furnace issues, always change the filter! Old filters can block the air flow. This actually limits the heating capability of the fan as it blows through the clogged and dirty filter. Some furnaces will actually shut down the burner if the filter is clogged so the furnace doesn’t overheat.