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Peerless boiler nat gas model number 61-04-STDG-SP

Boiler rating 304 sq ft of steam doe rating 97000 btu steam hr.
My question is in 3 parts.
First a little background. brick house built in approx 1920 4000 sq ft
I had the boiler installed by a plumber who wasn't good at steam so he did the heat calc using the wrong math with a software app designed for heat loss, not the correct way I learned at one of Dan's excellent seminars using square feet or load. approx 850 square feet+- %15.
System is two pipe steam with Hoffman 33 steam separator 1 1/4 pipe wet return 3/4 supply to rads 1/2 to dry returns.
Approx 2" supply covered mostly by asbestos insulation to 1 1/4 risers to second floor also asbestos covered.
Near Boiler piping is akin to "moose antlers". Should have a bigger plenum [steam chest] and drip to Hartford loop.
Replaced pressuretrol with vaporstat 0 to 4 psi. low water cutoff control was Cycle Guard 400 replaced with McDonnell & Miller PS-802-24
I recently replace part of the wet return, it was not replaced at the time of install.
I recently replaced the 24 volt transformer and the low water cutoff switch which leads me to the problem at hand.
The boiler had stopped working when I was on vacation in Florida 2 years ago. Tenants called I got a plumber and asked him to look at the issue.
Boiler was fixed or so I thought, fact learned later the plumber hot wired the system to run and left.

Last year and this water hammer which was a problem because of low water condition but low water cut off was NOT working.
I replaced LWcutoff yesterday and found out the truth.
Plumber used a jumper to fix a problem with the damper which hasn't worked since. Boiler now runs out of control vaporstat and low water cut off have no effect on operation, when power is applied boiler runs when power is not applied gas valve closes and only pilot is on.
If I didn't have a pressure relief valve I'd be talking to you from the moon.
1. Where can I find a decent troubleshooting plumber who understands steam in the Jersey City area?
2. Can I get some simplified wiring diagram for my boiler so I can get the wiring to work properly?


  • dlampe
    dlampe Member Posts: 5
    Part one answered thanks
  • KC_Jones
    KC_Jones Member Posts: 5,081
    Start looking on page 17
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • While you are waiting for JStar/Thatcher, (one of our best here), you can check the following.
    One or more of your radiator, or crossover traps may not be working, and allowing steam to get into the returns. Feel the outlet of each trap for excessive steam hot heat.
    That system, when all is properly configured, may function pretty well even when undersized (according to proper steam sizing methods). Do a search here for Dave Bunnel, Boilerpro, steam whisperer. He has written extensively on under sizing 2-pipe vapor systems.--NBC
  • dlampe
    dlampe Member Posts: 5
    System though under sized for the amount of Sq Ft of loading does work. I have changed all steam traps some twice. I have changed nearly all valves and I will be installing orifices and thermostatic valves next I understand the need to check steam traps and to understand what steam hot trap means steam is entering the dry returns. I think I have solved that problem for now.
    I have sent an email to Thatcher but his website isn't working so maybe he didn't have time to respond to the email.
  • dlampe
    dlampe Member Posts: 5
    Joe Star was able to rewire the system and get it running again.
    Thanks Joe!
  • JStar
    JStar Member Posts: 2,752
    Always happy to help. I didn't think I would see a Hoffman Vapor system in your neighborhood.

    Also, I'm currently typing this on my repaired ipad screen.