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Can anyone tell me if there is an adverse effect on a chimney that has nothing exhausted through it? Recently I had a gas and gas along with a 30,000 btu space heater and water heater disconnected from my chimney and the exhaust holes blocked. I'm curious since there is no heated exhaust being vented out of the chimney if the chimney will deteriate faster from the weather entering it. The chimney is from 1920 and has no kind of cap on top of it. I can get the gas company to cap it if there is going to be any negative effect from nothing being vented out it. It also doesn't have any kind of a liner in it.


  • Jamie Hall
    Jamie Hall Member Posts: 23,419
    It should be capped. It will deteriorate remarkably quickly, as it will get damp (and perhaps freeze) and never dry out.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • SuperJ
    SuperJ Member Posts: 609
    IMHO, In the age of high efficiency equipment residential masonry chimneys are rapidly becoming obsolete. Decommissioning and removing the chimney will often let your eliminate some rather substantial air leaks in your room.

    Getting chimney's restored or repaired by a brick layer is eye wateringly expensive, and justifies switching to high efficiency and just getting rid of the liability.
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    I would cap it as well. If it's not lined, do you just want to keep it for aesthetic reasons? As @Jamie Hall said the key to keeping masonry alive is to keep it dry. Warm exhaust does that normally, and a cap would do that when not in use.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • Harry_Harry2
    Harry_Harry2 Member Posts: 5
    Just as I thought but I was told that what was done meets state laws so it didn't need anything more. They couldn't vent my high efficiencie boiler to it and ran intake and exhaust out my cellar window. I was concerned that not having any warm exhaust air to dry out the interior of the chimney would cause early failure. I don't really need it for astetics but if I ever decide to put in a wood burning stove it would be nice to keep it in good condition.