Black Soot on Rads, Walls, Ceilings
Black Soot on Rads, Walls, Ceilings
(OP)
Hi,
I've encountered a problem that I need help with, here's what I've got: a duplex, built in the 50's. In the basement of one of the duplex's, there are two gas-fired hot water heaters servicing both unit's domestic hot water, and one gas-fired boiler servicing both unit's hot water radiators. About a year ago, one of the heaters was replaced, and soon thereafter there was a black, sooty residue collecting on the rads, walls, and ceilings in the duplex that is above the appliances (the other duplex is experiencing none of the problems described here). My initial thought was that the breeching and chimney stack were undersized as perhaps a larger HW heater was installed, but that's not the case, the heater was simply changed out, same model went in. I then thought perhaps there was not enough combustion air entering the building. However, there have been no renovations, no weatherstripping added, no improvements done to decrease the amount of infiltration into the building. So, how is the black soot forming? The local Gas Company went down and investigated, possibly products of combustion weren't venting properly, but they say everything is in working order, only that the boiler needs a cleaning. The people living there are complaining of respiratory problems and headaches. The gas company did CO detection testing throughout the space and came up with nothing. Has anyone any thoughts as to the formation of the black soot? We're stumped and concerned for our clients health. Any information or comments would be greatly appreciated. Thanks.
I've encountered a problem that I need help with, here's what I've got: a duplex, built in the 50's. In the basement of one of the duplex's, there are two gas-fired hot water heaters servicing both unit's domestic hot water, and one gas-fired boiler servicing both unit's hot water radiators. About a year ago, one of the heaters was replaced, and soon thereafter there was a black, sooty residue collecting on the rads, walls, and ceilings in the duplex that is above the appliances (the other duplex is experiencing none of the problems described here). My initial thought was that the breeching and chimney stack were undersized as perhaps a larger HW heater was installed, but that's not the case, the heater was simply changed out, same model went in. I then thought perhaps there was not enough combustion air entering the building. However, there have been no renovations, no weatherstripping added, no improvements done to decrease the amount of infiltration into the building. So, how is the black soot forming? The local Gas Company went down and investigated, possibly products of combustion weren't venting properly, but they say everything is in working order, only that the boiler needs a cleaning. The people living there are complaining of respiratory problems and headaches. The gas company did CO detection testing throughout the space and came up with nothing. Has anyone any thoughts as to the formation of the black soot? We're stumped and concerned for our clients health. Any information or comments would be greatly appreciated. Thanks.





RE: Black Soot on Rads, Walls, Ceilings
Could you post some numbers on the domestics hot water heaters, boiler and any other gas burning appliances in the space: how many BTUs from the nameplate.
RE: Black Soot on Rads, Walls, Ceilings
RE: Black Soot on Rads, Walls, Ceilings
Maybe you have a humidity problem. Check out the black sooty stuff for microbes, like moldspores,etc.
Just a stab in the dark!
pennpoint
RE: Black Soot on Rads, Walls, Ceilings
Pennpoint, there is no humidity problem, we're up in Winnipeg Canada, and we are dry and cold in the winter, especially in older houses that experience high infiltration rates. Thanks for the input though.
RE: Black Soot on Rads, Walls, Ceilings
If the black sooty material is produts of combustion they must be coming from the stack. Is the BTU input rating of the new heaterthe same as the old one? If so the stack may indeed be too small? A gas flame if properly adjusted should not give off sooty smoke or particles. Check the flame for the appropriate amount of combustion air. Is soot accumulating in the combustion chamber of the heater?
When installing the new heater the stack could have been moved and disconnected inside the wall. I am assuming it is a double or tripple wall metal stack.
RE: Black Soot on Rads, Walls, Ceilings
Thanks for your input.
RE: Black Soot on Rads, Walls, Ceilings
RE: Black Soot on Rads, Walls, Ceilings
RE: Black Soot on Rads, Walls, Ceilings
RE: Black Soot on Rads, Walls, Ceilings
RE: Black Soot on Rads, Walls, Ceilings
definitely check exhaust gas paths for any obstructions, check combustion air supply, the flame itself (should be a nice blue color with slightly yellow tips. note the shape of the flame.), and check the fireside of the boiler itself for soot deposits. lastly, you might want to contact a reputable service representative to investigate. soot deposits represent a potentially hazardous situation.
-pmover
RE: Black Soot on Rads, Walls, Ceilings
My guess is, something happened during the replacement of the the new unit.....like there must be something blocking the common vent...is there a barometric damper on the chimney?
The other possibility is the new unit might not be exactly the same type as the old one....is it power assissted or natural draft.....you should check and make sure the new and old units are TYPICALLY the same type.....