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Peerless Install

Brirob Member Posts: 12
Hi all. I'm in the middle of installing a Peerless 05L boiler, building a new header, and fixing a bunch of piping issues. Before I go much further, I have a couple of questions for the pros.

A little background - When we bought our current house a few years ago, the existing boiler was piped horribly, poorly maintained and looked to be on its last leg. It was sized about right for the radiation in the house at the time. During the first season, we found that the house was massively over radiated, as many houses of this era were - built in 1926, 3200sf, single pane steel casement windows with interior storms, spotty insulation. I did a manual j and came up with about 88k btu design day heat loss. Radiation was ~800sf EDR so a theoretical output of 192k btu. The whole house would consistently overshoot but some rooms were unbearable. We started shutting off superfluous radiators and found that the house still heated fine. We ended up with about 520sf EDR so the existing boiler rated at 733sf, became quite oversized and cycled on pressure more than I'd have liked. The vaporstat was set for 8oz cutout and 2oz cutin. Toward the end of last season, I noticed we were using a lot more water than normal. Filled the boiler to the risers and found a leak. There was a penny size hole near the top of one of the sections. Decided to buy a right sized boiler and fix all the piping issues in the house over the warm months. This is a Dunham vapor system and all the original piping that is still in tact is a work of art. Unfortunately, it's been hacked over the years. I'm slowly getting it all back to its original state.

I did steam and hot water work professionally for some years in my youth so I know how to spin a wrench, thread pipe and all that. Fortunately, I've held onto most my tools - 700 (Pony), 300, 141, 65r, 12r/00r drop ins, wrenches up to 48", and a bunch of other stuff. Never been able to part with them. I still maintain steam systems for a few rental properties and help friends out on occasion.

Sorry for the rambling...on to the questions-

1) Header Height - I piped up the header using nipples and mi fittings I had on hand (would rather have used domestic ci steam fittings everywhere but couldn't justify the cost - everything below the waterline is domestic ci fittings). The bottom of the header is about 30" above the max water line, about 20" above the top of the boiler. This is well above the manufacturer's 24" above waterline minimum standard but I know some here go higher if headroom is available. Also, I went with two 3" risers into a 3" header (overkill for the 05l I know) so velocity will be quite low - around 12fps. Wondering if I would get any drier steam by adding another 4-6" so I meet that 24" from the top of boiler standard many on here prefer.

2) Crossover Traps - I replaced the original Dunham crossover traps with B&J 122s when I bought the house. Steam gets to the end of the mains relatively quick. Don't have an exact time but within a minute of two of the header getting hot, steam gets to the end of the main. On one pipe systems, which I have the most experience with, I always tried to add as much main venting as possible but not sure how to approach this on a vapor system with crossover traps. The fittings on both the end-of-main and the dry returns are 1-1/4" bushed down to 1/2" for the traps. I have a few B&J Big Mouth traps left over from another project. I was thinking about building a 1-1/4" manifold and adding Two Big Mouths and the existing B&J 122 to each main. At 2oz, which is about what I average, that would give me about 6.6cfm vs the 1.8cfm with the 122 alone. It seems to me that these vapor systems would benefit from faster main venting the same as a one pipe systems would. Am I'm on the right track here? Is it worth the effort?

Image below of where I am so far.

Thanks in advance for any help.
WMno57Mad Dog_2Alan (California Radiant) Forbes


  • ethicalpaul
    ethicalpaul Member Posts: 4,806
    edited September 18
    1. You made a drop header (interestingly not actually supported by Peerless), so your header height calculation is basically moot. You are fine.

    2. steam gets to the end of your main 1-2 minutes after it is at the header and you want to make it even faster? I'd think there were bigger fish to fry.

    PS: looking good, but a couple questions:

    Are those 2-1/2" supplies? If so that's good (the manual says dual 2" are fine). The manual does call for a 3" header, but I can't see it mattering in your case with that nice drop header and those dual supplies. I guarantee you won't see any water in that header.

    Is your supply coming off of your header just a single 2"? That seems too small for this boiler, but again i am confident it will be fine, but out of curiosity, what is the size of your main?
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
    STEAM DOCTORAlan (California Radiant) Forbes
  • Brirob
    Brirob Member Posts: 12
    Thanks for the response. One correction, it's 30" to the bottom of the first 90 at the top riser not the bottom of the header. I probably wouldn't have done a drop header for this boiler but I already had it built up from my old boiler so it just needed to be modified slightly.

    The risers out of the boiler tappings are 3" and so is the header so it's all 3" to the supply takeoff tees. There are two 2-1/2" supply takeoffs. The way it was originally piped, there was a single 3" supply that went into a reducer tee a few feet from the boiler and fed the two 2-1/2" mains. Both mains are 2-1/2" for their entire lengths. Original piping image is below. I decided to drop both main supplies back to the header.
  • ethicalpaul
    ethicalpaul Member Posts: 4,806
    Oh cool, I see the second supply coming off the header now, it was hiding!
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • Mad Dog_2
    Mad Dog_2 Member Posts: 5,835
    You need a Job, sir?  Excellent so far...You're killing it.  Mad Dog 🐕 
  • Brirob
    Brirob Member Posts: 12
    edited September 21
    @ethicalpaul - I think you're right. Much more important things to think about than venting at this point. I think I was just itching to use those Big Mouths somewhere 🙂. I'll properly time steam from header to end of mains when I get things up and running and see if there's any room for improvement.

    @Mad Dog_2 - Thanks! I don't think I could do this for a living at this point. Everything hurts from working on this one install for the last few days lol.

    I managed to get the equalizer and Harford loop mostly made up today. Also got the first supply tied into the first main. Hoping to get the other main tied into tomorrow. Forgot how much fun the 141 was to schlep around.

    Mad Dog_2ethicalpaulAlan (California Radiant) Forbes
  • Dave0176
    Dave0176 Member Posts: 1,177
    Nice job, that piping arrangement looks mighty familiar!!
    DL Mechanical LLC Heating, Cooling and Plumbing 732-266-5386
    NJ Master HVACR Lic# 4630
    Specializing in Steam Heating, Serving the residents of New Jersey


    I cannot force people to spend money, I can only suggest how to spend it wisely.......
    ethicalpaulMad Dog_2
  • Brirob
    Brirob Member Posts: 12
    Thanks Dave! I imagine that piping arrangement does look familiar 🙂....saved a bunch of images of your installs for inspiration. That equalizer piping arrangement was quite tricky.
    Mad Dog_2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 5,835
    Ha ha...you see?? Anyone can do a stellar job if they take their time, imitate success and take pride in their work..We didn't invent this...The Deadmen did...In the early years, I learned the most about craftsmanship and pride on Renovations.  They'd gut the walls and reveal a Battery of 10 Water Closets with perfect precision wastes and vents, The Copper Crotons...picture prefect.  Same with an old Boiler that was piped carefully.  Artwork.  "Imitation is the greatest form of flattery."  Great looking job.  Mad Dog 🐕