Why Is My Furnace Filter Black?


Your furnace will likely be in an area of your home that has a lot of dust, dirt, and other contaminants. The air filter inside the furnace will help to remove as many of these items as possible. However, if the filter is black, it should be replaced right away.

Particles Make The Filter Black 

The particles that the air filter collects will cause it to change from white to black over a period of several weeks or months. As a general rule, there is no reason to be alarmed by the change in color. However, an air filter can only trap so much material before it becomes clogged or otherwise ineffective. Therefore, be sure to either replace or wash the filter in a timely manner. Signs of a dirty air filter may include a furnace that short cycles regularly or only blows cold air throughout the house.

Be Sure To Check The Air Filter Regularly 

It is in your best interest to check the air filter at least once a month to ensure that it is clean enough to keep using. This is true even if you schedule regular furnace inspections. During a furnace inspection, the folks at True Heating & Cooling in Broomfield can check the filter to ensure that it is in good condition. Our professionals may also be able to repair or replace your furnace if it is not working correctly.

Use The Right Filter 

It is important to use a filter that is the right size and shape for your furnace. Otherwise, it could fall out or be less effective at keeping dust or dirt away from furnace components. You can ask us about the process of choosing a filter during a service appointment.

The next time your furnace or air conditioner needs service, do not hesitate to give us a call right away. We’ll also be able to help with indoor air quality assessments or tests for carbon monoxide within your home.