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Installing WM EGH-85 Gas Stem Boiler - have riser piping questions


This is a followup to an earlier post "Installing New WM EGH-85 Images of existing piping attached looking for comments if OK to keep as is" on 10/22 where several of you were a huge help with guidance on my piping planning.
I think i have a good plan, but have one question - I have 2 3" mains running to opposite ends of my house. My plan was to come off my 4" drop header with 2 3" risers to each main. My contractor said I might just come off the header with 1 riser to a Tee to feed both mains. Is this OK?

Also, I have attaches a pipe and fittings BOM. I am coming out of the black with 3" risers, into a 4" drop header, out of the header to the 2 3" mains and out of the end of the header to 1-1/2" equalizer and hartford loop to the wet return
Anything I missed?

Last, a good steam guy here has suggested that since this is a single pipe steam system, I put in a condensate reservoir & pump & associated controls to ensure the boiler doesn't run dry Is this a good idea? What would this entail, ie parts required to do i & the right nomenclature so I can get pricing and plan ahead?

Thanks again in advance for all your help


  • BobC
    BobC Member Posts: 5,306
    edited October 2015
    I'm just a homeowner but I would feed each steam main with it's own riser off your steam main, using a T to feed both mains can be real trouble. Make sure both the feeds to the mains are between the equalizer and the two boiler risers -

    That drawing does not show a drop header but it does show the two boiler supply risers connecting to the header next to each other as they should be.

    Is there a reason why a condenser receiver and pump might be necessary? Gravity returns are simple and very reliable.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • MikeMens
    MikeMens Member Posts: 30
    Thanks. re: condensate tank/pump - he expressed concern that the new boilers are very efficient and create steam so fast that the boiler water level could run low before the condensate has a chance to refill the boiler. Said its a standard practice for many of his installs.
  • BobC
    BobC Member Posts: 5,306
    Lets wait for some of the pro's to chime in, Did the old boiler have the receiver and pump?

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • MikeMens
    MikeMens Member Posts: 30
  • Jamie Hall
    Jamie Hall Member Posts: 18,924
    I would come off the drop header with a separate riser for each steam main. I definitely would NOT take a single feed up and then a T to go into the two mains! Do it just as you are suggesting. A small amount of extra pipe and another fitting or two -- and you'll get much much better quality steam.

    I would not put in a condensate reservoir and pump. They are a bl***y nuisance, and very rarely if ever needed on a home system, even very large two pipe systems.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Fred
    Fred Member Posts: 8,518
    Stay with your original plan and tie each main into the Header, individually and nix the condensate resevoir and pump. Just not necessary.
  • KC_Jones
    KC_Jones Member Posts: 5,081
    It sounds like you have a couple of knuckleheads that don't know what they are doing. Stick to your plan and listen to the people on this site. You might also refer those people to this site for some MUCH needed education on steam. All those suggestions they are making are the sure signs they don't know what is going on. You make the plans and they can turn the pipe, stick to your guns on this one. And seriously don't add a tank. If it wasn't needed before it won't be needed now. It is a good way of spending money for no reason though.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,564
    There are some plans in the W-M piping diagram for a condensate reservoir, but I would determine that it is really needed before adding that in. It is basically a 5 inch x3 ft. pipe at waterline height, and connected to the return. As the waterline would drop, it will give up some extra water to the boiler. There is also a connection to the equalizer to vent it to the steam side.
    Skim as soon as you have finished the piping to reduce the possibility of surging water levels, which would cause some problems with dropping water levels.--NBC
  • vaporvac
    vaporvac Member Posts: 1,520
    And just so you're clear, a reservoir is not a condensate tank/pump. There is no pump with the reservoir. I'd make a plan for it, but not install it until you see if it's necessary. Follow @nicholas bonham-carter 's recommendation for skimming as surging can mislead you about your water level.

    I have a much larger two-pipe system and have not found the need for a reservoir tank. I have gone off on LW at the beginning of a cycle after a deep set-back, but never on subsequent cycles. Even that hasn't been a problem as most rads are heated by that time. It's the rare system that would merit one. A tank with a pump is just a needless complication and maintenance issue.
    Definitely take off each main separately as you plan. Otherwise how does the steam know which direction to go?
    Caveat: I'm just a HO like yourself, but went through these same issues with my own install. Slantfin and the fine folks on this site helped get me through.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF