I have a oil fired hot water heater. Not a part of my furnace. It is vented into a 6 in insulated metal chimney. there is a small hole in the first foot of stove pipe off the heater. Was put in at time of installation several years ago. I am getting piles of light black flaky ash out that hole that piles up on the top of the heater. I have taken the pipes apart and cleaned it, it still comes back. I first noticed this ash after having its annual service. I've been outside and seen this ash puff out the chimney and float around. Is this dangerous? This heater uses very little oil. I have a carbon monoxide detector in the area that has not gone off and tests ok.
thanks
thanks