Soot from boiler on basement furniture


Old 12-29-17, 08:20 AM
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Soot from boiler on basement furniture

We had a portion of our basement finished a few years ago and the boiler was enclosed in a closet with vented doors. While I assume most of the exhaust is going up the flue, some must come into the closet and then out into the room. Does this indicate a flue problem? if not, is there anything we could do? can we close off most of the vents on the doors? is there a filter that could be added to the flue that would limit the soot coming out? There isn't a lot of soot but over a few weeks if you wipe a rag across the furniture you pick some up.

We have a P-WGO-6 Weil Mclain oil boiler

Thanks for your help!!!
Old 12-29-17, 08:31 AM
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The most likely cause is a lack of combustion air. The best way to solve that problem is to seal off the closet door & bring air from outside into the closet or directly to the burner.
Old 12-29-17, 08:36 AM
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thanks for the quick response.
the house is about 20 years old and so is the boiler. would it be normal in an unfinished basement to source air from the outside or is this something that possibly should have been done when we finished the basement?
Old 12-29-17, 01:36 PM
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The boiler needs an air supply for combustion. It will get it from wherever it can. If not supplied from outside it will get it from the basement or living areas. Anywhere there is an opening for air to travel.

It started to become more of a problem when the houses started getting tighter. The older homes had so many points of air infiltration it really didn't matter about bringing in outside air.

That being said, even with the louver doors you may not being getting enough combustion air. An efficiency or combustion test would tell you that.

No matter how old your boiler is and 20 yrs. old is not that old you should not be getting soot outside your boiler, never mind around the room.

Soot is nothing more that a dirty burning fire from the wrong air/oil mixture. It could be created by the lack of combustion air but may also be caused by the burner not being adjusted properly, the wrong size or defective nozzle or the burner just not being set up properly. You cold have a plugged boiler which will happen eventually if your boiler is making soot.

Check your chimney for proper draft to make sure your combustion byproduct is going up the chimney and not in the house.

It's one thing to have the mess from soot getting everywhere but for me, the bigger picture would be why is it getting in the house where I am breathing this stuff instead of going out the chimney where it should go.

In any case your boiler, properly set up should never be making soot that gets outside the unit and should be addressed.

Have someone come in with the proper test equipment and set up your boiler and if you want, try opening those louver doors at least temporarily to see if it makes a difference.

If your boiler is not set up right no amount of fresh combustion air will help.

Hope this helps a little.

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