Clare Gas Furnace

Hello Dear
I have a Clare Gas Furnace ( 1991 ) and I noticed lately black dust on the ceilings, toilet, bathtub walls etc., everywhere there is a heating vent.First I thought I installed the filter the wrong way, but that was not the problem, can somebody help me ??

Regards, Nicole

I would recommend having an HVAC technician check the unit ASAP!!! Could be a damaged heat exchanger. Danger of Carbon Monoxide exposure!!!

Safety First!!