Your furnace filter is an important part of your heating system. As air flows through your home, the furnace filter removes dust and hair from the air supply. This helps your climate control systems work more efficiently and can also improve your indoor air quality. In order for the filter to do its job, it must be cleaned or replaced regularly. Most of the time, when you inspect the old filter, you will see the gray color of accumulated dust. Sometimes, you will pull out a surprisingly black filter.

Is It Mold?

At Summit Heating, A/C, Plumbing & Electrical, it is not unusual for a customer to call concerned about a black color on their furnace filter. Mold is one possible culprit. Some furnace filters are washable. Instead of throwing out the used filter, customers can clean it with a hose or in a basement utility sink. However, if they do not allow the filter to dry completely, mold can grow, especially if the filter is located in a damp basement.

Is It Soot?

The main reason we see black furnace filters is soot. Soot is the carbon byproduct of combustion. When we find soot on a filter, it is important to find the source. It may be something simple like a home where scented candles are infrequent use. You may only notice smoky soot when you blow out the candle, but in fact, soot is constantly released into the air while a candle burns.

Soot can also be a sign of a gas appliance that is burning improperly. If you have a gas furnace or water heater, check the flame. If it is burning correctly, you will see a bright, blue flame. If it is burning inefficiently, you will see yellow or orange. The incomplete burning of the gas is the source of your soot. If you see a yellow flame in your furnace, call a furnace technician to correct the problem right away.

Summit Heating, A/C, Plumbing & Electrical is dedicated to keeping the homes of our customers in Denver and surrounding areas comfortable throughout the year. We are ready to help you handle your heating, cooling, and air quality needs. If you find black on your furnace filter or have any other concerns about your heating or cooling system, contact us today.

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