Why Would a Furnace Filter Turn Black?

November 5, 2019

Furnace unit

Updated: February 16, 2024

If a furnace filter does its job the right way, it won’t stay the same color. The filter will slowly turn gray. After all, the filter is collecting dust and dirt. It wouldn’t hurt to pull the screen before its replacement due date and vacuum it clean. If you remove the filter and it’s pure black, this should cause some alarm. Some reasons for a black filter are serious ones.

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. However, the gas could come from another source. For example, it could enter a home from the garage. Vehicles produce carbon monoxide when they run and idle. Regardless of the cause, addressing the problem must become a top priority. Since this gas is odorless, you won’t notice it without the assistance of a carbon monoxide detector. If the leak source involves the heating equipment, get the repairs done right away. The heating experts from Brennan Heating & Air Conditioning are available to assist you with furnace repair and maintenance.

Mold Grows Unnoticed

Mold grows in moist environments. You might not think your HVAC system fits the description of a suitable environment for mold growth, but it can be. During the hot months, running the air conditioner could create moisture in the evaporator coil. Moisture can lead to mold, which then ends up on the filter. Removing the moldy screen won’t be a complete solution. A professional cleaning may be unavoidable.

Contact Brennan Heating & Air Conditioning for HVAC cleaning service!

Soot Gets Into the System

Soot travels in the air and can end up on the furnace filter. Unfortunately, you may be breathing the soot into your lungs too. Where does soot come from? There can be many sources. A fireplace could produce it, but so can candles.

Take immediate action to care for your furnace. Call Brennan Heating & Air Conditioning today to discuss any necessary service in the Seattle or Tacoma areas. We perform a full range of heating, cooling, and electrical services, including AC repair and furnace maintenance. We can also help with your water heater installation services.

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