My unit blows out black soot looking stuff, and it smears when touched, and my filter is clean. What is it? And how can I get it to stop?

filter is degrading and is coming out from inside the unit , replace filter with new one

I'd start with opening it up and carefully cleaning the entire insides, cleaning or replacing air filters, etc. If you continue to get black stuff, look inside and see where it's coming from. The blower motor may be going bad.

This sounds dangerous, I suggest you hire a pro to look into this.

Unfortunately, you failed to mention the Model Number and whether its a flue-less or Vented unit. In either case, the black streaks you see on the walls and ceilings is soot. If it's a flue-less unit, this is an indication that the unit has not received routine maintenance on a regular basis. The sooting is caused by a dirty or clogged burner or low gas pressure.

Also, burning scented candles and operating the heater at the same time, will cause soot. Not from the heater, but from the candles. All candles soot, but scented candles soot more than others. Combine them with the warm moist heat and they will soot 50 times worse. If this is the case, it's the candles sooting, not the heater. Stop burning the candles while the heater is in operation.

Is the soot dangerous? Yes, to the point that you are breathing it in, when it;s floating in the air. The sooting didn't occur over night, it has been doing it for sometime. You finally realized it, when you saw the black streaks. Stop using the heater until it is professionally serviced by and authorized Rinnai Service Technician and the walls and ceiling are cleaned.

You can either remove the soot yourself or have it professionally done. Then, you should prime paint the walls and ceiling with a sealer like Kilz, before repainting. All curtains or draperies should be washed or dry cleaned. All furniture and carpeting should be vacuumed thoroughly.

I hope this helped you and thanks for choosing FixYa.

If its a thru the wall or a window unit, they have a foam air filter, and the insulation is dark color.

If these are electric base board heaters, that is probably not soot, but instead mold. Put a little bleach in a spray bottle and try spraying it right on to the black soot looking stuff and see if it will disappear. If it does, it is mold. Bleach will kill the mold.

If these are gas heaters you need to call a service man NOW. Black soot is a sign of gas burning raw and can be very dangerous. Turn them off if this is the case.

Sounds like your filter is coming apart. Take the unit out and wash it with a water hose. Clean it but try not to get water on the switches. Put it back in but do not plug it up immediately let it set for 15 to 30 min. I also use a shop vac to **** excess water ect... out of the unit after i clean it. good luck

you have a problem with combustion.unit is not burning properly you should turn unit off and call a pro the life you save may be your own

I had the same problem and then found that it was from burning aroma candles! I will never burn them again!