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Steam Boiler replacement BTU question

<a href="file:///C:/DOCUME~1/John/LOCALS~1/Temp/msoclip1/01/clip_filelist.xml">


I am changing my steam

boiler from oil to gas. I currently have a HB Smith boiler with a Beckett

blower with a .85 nozzle. I looked at the Weil McLain instructions on there

website and calculated my radiators to be only 46,905.04 BTU’s. I also have a

hot water loop in the basement with a ten-foot baseboard. The plumbers I know

tell me I should use a 100,000 BTU boiler. Is that too much?  I just want it to be efficient as possible.

The system I use now seems to use a lot of oil for a small house, total 1066 square

feet for the first and second floor. My roofline is steep so the second floor

has a lot of un insulated roof on the walls but the attic floor is insulated.</a>


  • JohnNY
    JohnNY Member Posts: 3,102
    Boiler sizing

    There is no good reason to install a boiler that is more than twice the size needed to fill radiators with steam.

    It leads to inefficiency and imbalance.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Plumbing in NYC or in NJ.
    Take his class.
  • Steamhead
    Steamhead Member Posts: 15,903

    if it's using a lot of oil, the boiler may or may not be the problem. Have you had a Steam Man look at your system?

    Try the Find a Professional page of this site.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Tim McElwain
    Tim McElwain Member Posts: 4,580
    Based on your

    BTU on the radiators a boiler around 75,000 is more than enough and if you get a Mod/Con boiler with outdoor reset  you will be able to dial it in for real good efficiency and comfort. I would also however have a heat loss done on the house to be able to match that up with the radiation. I might also suggest TRv's on the radiators with constant circulation.
  • Tim McElwain
    Tim McElwain Member Posts: 4,580
    Whoops I should go to bed

    I am tired I didn't realize your boiler was a steam boiler, sorry. Still I would have a heat loss done and as Steamhead suggested you may have issues with the system itself.
This discussion has been closed.