Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Resources on best testing/setting for single steam pressuretrol setting?

Hey guys,

My sister has just had her boiler replaced. She lives in the bronx, NYC and the process has been a nightmare. The contractor she worked with was really bad, after the boiler was replaced a lot of the distribution pipes started leaking and the contractor wouldn't fix them, so she had to.

She started asking me if it was operating at too high of a pressure and sent me the attached pic. I just bought Dan's book for her for a resource, but can you recommend any resources on setting and adjust the pressure troll?


  • Jamie Hall
    Jamie Hall Member Posts: 22,897
    Don't know what you mean by resources

    other than us -- and our experience.  Or Dan's books...

    And, based on that, that pressuretrol is set way too high.  The main scale should be set at 2 (setting below that can create problems with the linkage -- although it would nice to be able to set it lower) and the diff. (differential) scale should be set at 1.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Chris_Williams
    Chris_Williams Member Posts: 8
    Scrolling through past posts

    I know there's a tons of threads on this, I'm trying to find them right now, but if anyone has the URL off the top of their head, let me know!
  • Chris_Williams
    Chris_Williams Member Posts: 8
    Thanks Jamie

    Thanks Jamie, would there be a risk setting the DIFF to .5 PSI?
  • MDNLansing
    MDNLansing Member Posts: 297
    Just Slide

    Just slide the Main (grey) one to 2 and the Diff (white) one to 1. That's really all there is too it.

    As Jamie Hall stated, don't lower the Main below 2 or the linkage might bind up.
  • Rod
    Rod Posts: 2,067
    Pressuretrol Setting

     Hi- Go with Jamie's recommendations. He's very experienced.   Residential steam systems operate at a maximum of 2 PSI  (Even the Empire State Building's maximum is 3 PSI) 

    Set the Main scale at "2"   and the Differential scale at "1".   That means when the thermostat starts the burner, that the pressure will build to 2 PSI before the Pressuretrol shuts the burner off.  As the pressure drops, the pressuretrol will then turn on the burner  when the pressure reaches 1 PSI. This cycling between 1 PSI and 2 PSI will continue until the temperature setting on the thermostat is satisfied.  If you want to try a sightly longer cycle you can change the Differential to "1.5" but leave the Main at "2".  That means it will cycle between 1/2 PSI and 2 PSI.

    - Rod
  • ChrisJ
    ChrisJ Member Posts: 15,442

    I didn't see anyone mention if but if it has been said I'm sorry for repeating.

    To adjust I believe there should be two screws on top of the unit you turn.  As you turn each one the sliders will move up and down.
    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
This discussion has been closed.