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Steam Boiler Options...which is best?

sm69th Member Posts: 5
So my old peerless boiler died and I need to get another. Have a little trouble as I get conflicting advice and quotes ranging from somewhat reasonable to outright absurd and they are sized all over the place.
I got rid of the estimates that tried to sell me a boiler without counting my radiators and just going off the old boiler size. I got rid of the quotes that were for a system about half the size i calculated I needed too.

I did a bunch of research, and was hoping some steam gurus might be able to give some advice.
This is what I know:
I have a 1913 colonial house with 3,509 sq ft, single pipe steam system with 18 cast iron radiators. I have already measured all the radiators, counted sections, and came up with requirements of ~721 sq ft steam/ 173,004 BTUs. My oil boiler appears a little oversized at 201,000BTUs/840 sqft of steam...it is also 30+ years old, probably not that efficient. Note, I do not care about hot water, I have a tankless system that runs on propane.

After much research, I had leaned towards a Burnham MegaSteam due to high efficency, dry steam, and other factors. HOWEVER the top MegaSteam model (MST629) only puts out 629sq ft steam/151,000 BTU...which falls short of my calculated requirements. So it seems undersized for my house.

A couple people have said the MST629 would still work FINE in my house...something about how the estimates are calculated for the coldest of days so for all but the 7 to 10 really cold days of winter I will get plenty of steam and on those bad days the boiler would just run pretty constantly as it couldn't put out enough steam to keep up. Is this advisable!??! I DO have 4 working fireplaces I could fire up on the nasty cold days to compensate for the boiler struggling?

Sidenote: Burhman initially agreed to create a custom MegaSteam with a 5th section to get the BTUs up to 189,000....but then an engineer nixed the idea saying the extra weight wouldn't survive shipping and it would crack :-(

So if installing a undersized MegaSteam is a bad idea, here are my other options:

Peerless ECT-05 2.00 GPH, Eff: 84.6%, 180,000 BTUs, 750 sqft steam
Slant Fin TR-50H, 2.00 GPH, Eff: 84.0%, 179,000 BTUs, 750 sqft steam
Slant Fin TR-50H, 2.10 GPH, Eff: 83.4%, 184,000 BTUs, 767 sqft steam

Anyone have any suggestions? I wouldn't mind the megasteam if I knew it could heat the whole house!

Thanks in advance!


  • Steamhead
    Steamhead Member Posts: 16,904
    edited October 2014
    Unfortunately, we can't ignore the pick-up factor. Burnham needs to offer a larger three-pass steamer and make it available with gas burners, then they'd own the market.

    But both the Peerless and Slant/Fin are good units. Go with the best installer.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • j a_2
    j a_2 Member Posts: 1,801
    Agree, do your homework and find the best most reliable installer…Make sure he is a steam guy, and ask him questions, if he scratches his head, send him away…..Use the peerless steam survey available online….Its the installer not the boiler, so many manufactures get a bad rap, because knuckleheads installed them….
  • KC_Jones
    KC_Jones Member Posts: 5,742
    Also with steam it's about the maintenance. Can't ignore that! If you plan on the installer maintaining it, makes sure you ask questions about that as well. This is all part of getting a good installer. Do your homework. Your best defense against a bad contractor is being educated. You ask questions they should know the answers. Good luck!
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15