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Venting Issue??

ScottE Member Posts: 8
Trying to set-up Turbo Power (800,000 BTU). I have gas, air and nozzle adjusted to specs. I have -.02 -.06 INWC at the test port (12" from flue outlet) can not get my CO levels close 1500+. attached is a drawing of the venting and related. Venting issue or??


  • icesailor
    icesailor Member Posts: 7,265
    Venting Issues:

    I don't quite understand your drawings, but in my MA Plumbing and Gas CEU class this year, gas vent piping was heavily discussed. I looked in the workbook and I can't find any 8" pipe that will handle 800,000 BTU's. Perhaps your 1500 PPM CO is because you aren't venting enough?. Like your venting is too small?
  • Tim McElwain
    Tim McElwain Member Posts: 4,481
    If I get you picture

    correctly you are running an 8"single wall flue off your boiler 800,000 BTU's into a 12 inch flue connected to a 22" x 22" masonry (I hope lined inside) chimney roughly 30 feet tall with a lateral run of 20 feet. If that is correct an 8" flue is only 50 square inches and can not handle more than 327,000 BTU's so it is too small. I might suggest by the way using 12 inch all the way as it will handle 932,000 BTU's. An undersized flue will affect your draft which means poor over fire and will cause high Carbon Monoxide for sure.

    The next thing to consider is the chimney at 22" by 22" that is 484 square inches at the low end of 4,500 BTU's per sq in it will only handle 2,178,000 BTU's at 6,500 BTU's on the high end 3,146,00 so either way your total of 3,876,000 is too much for that chimney. If it is not lined that presents even more problems.

    What size is the breech on the boiler? What does the I and O manual call for? Is this being installed under CSD-1 requirements? If so then sizing may change some what based on what your boiler is specified under. You need to check with your local Authority Having Jurisdiction as to local specifications as they vary from say Boston one way New York City another way.
  • ScottE
    ScottE Member Posts: 8

    Thank-you very much...the original installer/consultant are back and resizing so hopefully they will get it resolved and they are starting with 12 inch for the heater

  • Tim_Hodgson
    Tim_Hodgson Member Posts: 60
    I'm glad

    the installing contractor is taking care of your problem. Most CO problems are caused by lack of air or too low of temperature. Excessive air can create problems too. Take an O2 reading along with the CO and temperature. A draft reading at the breech and over fire is good to have when all is set correctly. Deviations from the proper readings will also let you know when service is needed, Check them once or twice a month.

    Good Luck,

    Tim Hodgson
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