Why Is My Furnace Blowing Cold Air?

Here in Southwest Michigan, we get our fair share of chilly fall and winter days. When they arrive, we count on our home’s heating system to keep us warm, safe, and comfortable. As one of the most common types of heating systems, furnaces get widely used across Michigan. Unfortunately, like any machine, wear and tear can cause them to malfunction over time. This post will explain why a furnace may blow cold air and what to do about it.

The thermostat’s settings are wrong

If it’s early in the fall or winter season and you’re just beginning to use your furnace, your thermostat might be set for summer weather still. Take a look at the current settings as well as any scheduled settings. For example, was your home set to cool during the afternoon hours in summer?

Clogged air filters

There is no rule to determine exactly how often to replace furnace filters. But, sooner or later, they all get clogged with dust and other particles. So if you haven’t changed your furnace filter recently, try taking a look at it. Clogged filters can restrict airflow and by the time air reaches your vents, it may feel cool.

Leaky ductwork

Because of the way ductwork gets designed, they’re rarely 100% sealed. As a result, your heating system is likely losing some hot air through small cracks and openings in the ductwork. With proper ductwork, this is usually negligible. However, if your furnace isn’t blowing the hot air you expect, it could be leaking through damaged ductwork.

The pilot light or flame sensor is out

Many older furnaces have a pilot light visible through a small opening in the furnace. This pilot light is necessary to ignite the larger burner and warm the air to circulate through your home. If the pilot light is out, then your furnace won’t blow hot air. If you know where to find the pilot light, you can take a peak from a safe distance. It should be evident whether the flame is present.

Problem with the fuel supply

Aside from more visible symptoms of a furnace blowing cold air, there could be a less apparent mechanical issue. For example, there could be a problem with the fuel supply. If you have an oil furnace, it could have an empty oil tank. Gas furnaces could experience a weak or shut-off gas supply. If you think you may have a problem related to the fuel supply, call a professional for help with the matter.

Dirty valves or other sensors

There are many mechanical pieces required to operate the furnace. Gas valves, flame sensors, electronic ignitions, and thermocouples are a few. If any of these components malfunction, then you may find yourself in a cold house. If you haven’t tuned up or maintained your furnace recently, it may only need a thorough cleaning. Components of more neglected furnaces may need replacement.

As you can see, there are many reasons why your furnace may not blow hot air. However, you must address the problem immediately before minor issues lead to larger and more expensive ones. Not to mention you don’t want to go another winter’s day in a home without heat.

At Boelcke Heating & Air Conditioning, our expert technicians can diagnose and fix any broken furnace. We always do our best to repair your equipment, but we will also let you know if replacement is a better option. If so, you can also count on us for quality installation service and products. If your furnace needs repair in the Coloma, MI area, contact us today at (269) 429-9261, and we will be happy to assist you.