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Smallest boiler still too big.

RJMCTAFO Member Posts: 113
I looked at a replacement install this week and am unfortunately looking at a situation that I may be overthinking. The house only needs 140 sq ft. of of steam. The home has oil with no natural gas option.
I suggested going propane to get a boiler that is much closer to the required edr. Customer wants to stick to oil. The smallest mega steam is 288 sq. ft.
Is there anything I can do besides an oversized drop header to help this system?
Worried I am going to create headaches.


  • jumper
    jumper Member Posts: 1,719
    What does customer like about oil?
  • Abracadabra
    Abracadabra Member Posts: 1,948
    weil eg30 is 196sq.ft. which you should be able to downfire to get closer to the 140. maybe not all the way there tho.
  • kcopp
    kcopp Member Posts: 3,830
    Install the Mega Steam.
    Pipe it properly and you will be fine.
  • Steamhead
    Steamhead Member Posts: 14,864
    The smallest Crown Kingston is 246 square feet- that would get you closer:

    The smallest New Yorker CL is 233 square feet- closer still:

    These are both pinners though...............
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • ChrisJ
    ChrisJ Member Posts: 11,985
    I thought it was easy to downfire an oil fired boiler?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Steamhead
    Steamhead Member Posts: 14,864
    You don't want to go too far, or the stack temp will get low enough to condense the flue gases. Not a good thing.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Jack
    Jack Member Posts: 1,045
    Actual stack temperature remains above 350°F. I am quite sure there is a limited amount of condensing on a cold startup as the chimney is external to the building. However, in the colder months, the interior of the chimney probably doesn't fully cool before the next call.

    Hatteras, I think you are being very generous with/for this outside chimney's operation. Look at Appendix E in 31, talk to the boiler manuf and line that chimney. I've had success with 4" pellet vent as an insulated liner, which is what you likely need. Also, has the chimney been inspected per 31?
    At the very least, if you choose to use the chimney as is, I would inform the homeowner that it could likely or at least possibly be an issue now or in the future. The cost of a re-line should be considered in the LP/oil equation.
    RJMCTAFO Member Posts: 113
    Unfortunately the only boiler on the oil side that qualifies for the loan program is the Megasteam. If i wanted to put a propane boiler in they are ok with an atmospheric though. :|