Why are my furnace filters black?

If the dirt collected in the furnace is left wet for an extended period, sooty mold can develop and later spread to the furnace filter. Many of the central heating systems that are not cleaned regularly have grown mold, which causes the filter to have a black color.

What causes black on a furnace filter?

Carbon Monoxide Exposure

Carbon monoxide is probably the worst reason why a filter turns black. It’s a poisonous gas, and if it is leaking into your home, you and your family could be breathing it. The health risks are enormous. Carbon monoxide leaks may result from damage inside the furnace.

What does it mean when your air filter is black?

If you’ve recently changed out your air filter and noticed it was black, you’re experiencing something called “black soot deposition. Essentially, black soot deposition is just an excess build-up of soot, which is typically the result of: A gas appliance or fireplace that isn’t burning fuel properly.

Why is my furnace filter black after one week?

When you run your air conditioner, the evaporator coil will become damp from condensation. If left for a long period of time, that condensation will mix with the dust and dirt and form a black mold. This mold will grow and eventually spread to your furnace, and the filter.

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Should my air filter be black?

But while some dust accumulation on the air filter is normal, if you find your air filter is black, it could be indicative of another issue with your heating and cooling system. No matter which way you slice it, when you change your air filter, it shouldn’t be black.

Can a black air filter make you sick?

You get air filter black mold. As soon as you notice air filter black mold, dispose of the filters! Mold can make you and your family very ill. Symptoms of sickness from mold can include a sore throat, stuffy nose, coughing, wheezing and eye irritation.

Why does my furnace filter get dirty so quickly?

Leaky Duct Work

According to ENERGY STAR, a typical house loses 20-30% of air through leaks in the duct work and poor duct connections. Leaving these untreated can not only kill your furnace filter quickly, but also result in higher energy bills.

What does black mold look like on furnace filter?

You can typically identify black mold by its color. Many other molds are green or grey, but black mold tends to be a dark greenish black or gray color. It will appear around the home as a slimy, dark greenish-black or gray substance. Black mold grows off of moisture, releasing spores as it consumes organic substances.

What causes soot in a gas furnace?

Incomplete Combustion

As the furnace in your house burns fuel to create heat, especially natural gas, there are remnants left over after the process is completed. … One of the combustion byproducts is carbon, the primary ingredient in black soot, which is sent up the heat exchanger and out of the house.

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Can dirty furnace filters cause carbon monoxide?

Dirty furnace filters can restrict air flow and cause a backup of airflow in your heating system. When little to no air is passing through your furnace, its heat exchanger can overheat and crack, leaking carbon monoxide into your home.

Why is my furnace filter not getting dirty?

A filter is designed to catch all the air that goes through your air conditioning. Because of this, it needs to fit snugly inside the holder to have a chance at catching the air. … When that happens, the filter won’t get dirty because all that air isn’t going anywhere near it.