If you have a black filter and you are known to burn candles, especially scented candles, this could be the reason for the black filter. One way to find out is to stop burning candles and check your filter a couple of weeks later, if the filter is still black call an experienced HVAC provider to inspect your system. If the filter is not, candle burning is the likely culprit. The reason for this is every time you burn a candle, black soot is produced and this soot gets sucked into your duct system which then collects on your filter turning it black. If you don’t want to stop burning candles, there are a few things you can do to try and stop the black filter.
