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Chimney help

Jack_23Jack_23 Posts: 153Member
Since the 92 change to NFPA 54 the venting standards have become more and more restrictive concerning 80 % equipment and masonry chimneys. Masonry chimneys are not suitable for venting gas equipment. the physics are all wrong. They are oversized (look at the cross sectional area, 8x8 chimney tile is about 56 nominal sq" vs 6" liner at about 28 sq"), when a gas expands it cools. When it cools it condenses. The condensate is corrosive. If the appliance is oversized, and it always is, the short burn cycles further aggravates the problem as the chimney does not get up to steady temp. as there is no steady state operation. If the top bricks are loose it was not the chimney liner guys fault, although it was his responsibility to point it out and suggest repair, IMHO. Chimney tops are where you can most easily identify venting problems. Just look at the older houses in your area and see how many of the chimneys are "the leaning towers of Pisa". Rather than spend the money to line the chimney however your friend would have been money ahead ditching the chimney and upgrading to a condensing unit. or at least a direct vent of higher efficiency


  • Robert O'Connor_7Robert O'Connor_7 Posts: 688Member
    chimney help

    My neighbor recently had a chimney contractor (in my opinion) "scam" him in to thinking his chimney was dangerous. This bye the way is quite common. Anyway, the contractor installed a flex liner WITHOUT a permit. My neighbor called me that night and said his heat was off and could i help him. I discoverd the spill switch tripped, and told him there may be a problem with the install. I checked the height and size of the new liner and discovered that the liner was one size smaller than it should be. He called the contractor back and secured the permit, and the crew put another Larger liner in (the correct size).In the throws of the install the contractor moved the top portion of the brick and probably the first course tile. In doing so losened the top a bit. Now I see vapor trails coming from these cracks. Now the spec, Cold brick chimney with tile lining with the flex, Steam boiler 80%, water htr. 40 gal. std. efficiency. Now i know because it's a cold chimney (3 cold sides) there might be some condensing on the outer walls of the new liner inside the now sealed (capped top) the temp. this morning wasn't that bad @ 22f, and the chimney is drafting fine, the top smokey flume is very consistant with the other neighbors chimneys. Q? should this be a cause for concern, and should he check CO in the cracks?? Thanks Robert O'Connor
  • Mad DogMad Dog Posts: 2,595Member
    Sound advice...Jack knows his sh...ale......

    I see the same problem on a regular basis. Had a guy the other day that kept changing the spill switch! You can never go wrong testing for CO. Here on Long Island, they only started enforcing the liner rule on new boilersin JULY. The vast majority of companies in our area had no clue and the phone was ringing off the hook with no-heat calls. Reading NFPA 54 and UNDERSTANDING it is something that alot of guys refuse to do. If you need a good, honest chimney guy, I got one. Mad Dog

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • Robert O'Connor_7Robert O'Connor_7 Posts: 688Member

    Thanks guys. I agree with the chimney logic, however I borrowed a co tester and climbed on up there and discovered co upon futher inspection. I checked the top connection to see if it had come apart, it didn't, dug a little deeper and found that it wasn't even connected about 8' down. Now i stepped back and let the original contractor come back and say we messed with the install so he's not responsible, he left so we went into the basement pulled the liner from there only to find it was about 10' short. It wasn't even connected. Not even close. The HO /neighbor is finally getting a new one today (from a GOOD HVAC guy i know) And the town has already sent this scumbag a violation notice w/ order to pay penelty. Can you belive this? How can anyone do such a thing. He could of killed everyone.
  • Jack_23Jack_23 Posts: 153Member
    Certifed Chimney Sweeps

    Too Bad. Sorry for your friends problem. it was good of you to stay with it. Now, as to chimney guys. I've done work with the Nat'l Chimney Sweep Guild as a speaker and attnded a bunch of their shows over the years. Good people. As well I have spent more time looking down chimneys than I care to remember. this is the typ job that is scam prone. The Guild is very aware of that and the "real" sweeps are highly motivated to do it right. When looking for a sweep for a relining you need to make sure that the person is a "certified sweep" by the Nat'l Guild. Also, you might check their web site and post this story there. The good people who make a living at it will light that guy up...right now!!
  • jim_14jim_14 Posts: 261Member
    so whats the website

    for the certified chimney sweeps??
  • D. R. RiddleD. R. Riddle Posts: 3Member
    furnace vents

    Code question for NYC. Power vented exhaust has to be how far from an opening, such as window, etc ? How about gravity vent ? I have been told 10 ' but want to see it in the code. Unit of immediate concern will be a new installation of 300K BTU furnace. It's on the 4th floor of an old industrial building converted to open office space. There is only one more floor above. We'd like to shoot this exhaust right out a back window panel versus going out and up to the roof.
  • Jack_23Jack_23 Posts: 153Member

  • Jack_23Jack_23 Posts: 153Member
    For detailed drawing...

    go to
  • Mad DogMad Dog Posts: 2,595Member
This discussion has been closed.


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