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.
If our community has helped you, please consider making a contribution to support this website. Thanks!

What is this?

Options

Doing a steam boiler install and my co worker asked what this is. I said "no idea lol". Its a two pipe system and this is at the end of the re

turns.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 27,355

    Dunham Return Trap for Dunham vapour steam system. It's in The Lost Art — look it up.

    That system should be controlled with a vapourstat running at a cutout of 8 OUNCES per square inch or less.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    mattmia2
  • tylerjgardner
    tylerjgardner Member Posts: 14

    Interesting. What are the consequences if I run it at 1.5 oz? The old system had the standard pressuretrol (same as this new system)

  • ethicalpaul
    ethicalpaul Member Posts: 8,779
    edited March 25

    I think you mean your pressuretrol is set to 1.5 psi

    That is way too much especially since most pressuretrols that are set to 1.5 actually cut out between 2 and 2.5 psi

    (8 oz is .5 psi)

    NJ Steam Homeowner.
    Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
    See my sight glass boiler videos: https://bit.ly/3sZW1el

  • tylerjgardner
    tylerjgardner Member Posts: 14

    I mean 1.5 psi

  • KC_Jones
    KC_Jones Member Posts: 5,934

    If you sized the boiler correctly it shouldn't get to 1.5 psi, so it shouldn't matter. The vaporstat or pressuretrol are pressure safeties. On 2 pipe the sizing is extremely critical, I feel it's critical for all systems, but the 2 pipe are typically more sensitive to pressure, which is a function of boiler sizing. How did you size the boiler?

    I agree with Jamie though, it should have a vaporstat to ensure it doesn't have a chance of getting out of hand.

    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • tylerjgardner
    tylerjgardner Member Posts: 14

    So yeah I would LOVE to install a vaporstat, but the salesman won't want me to get a $500-600 part for this. Also the salesman sized this boiler- you guys are gonna love this- "the old one was this size so I got the same size boiler for this zone". Theres a lot of things I can see wrong with this install, but unfortunately I was told to just "slap in it exactly how the old was was". Im beginning to realize that the company i work for is the "knuckleheads" the Dan Holohan warns homeowners about lol.

    ethicalpaul
  • Jamie Hall
    Jamie Hall Member Posts: 27,355

    You ask the consequence of running the boiler up to 3 times the desired pressure.

    It won't heat as evenly (and indeed may be difficult or impossible to get anywhere near balanced). It may use more water than it should. Components such as radiator traps and the main vents will fail much sooner. It will use more fuel than it should.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    tylerjgardner
  • AndythePlumber
    AndythePlumber Member Posts: 106

    what Jamie said….your company is snaring a unicorn in a bear trap so the salesman’s wife can purchase overpriced facial creams and various other vanity accessories. Before the big war hard men crafted what you’re looking at. Makes me sick. It’s not your fault. Quit your job

    THINK

  • mattmia2
    mattmia2 Member Posts: 16,739

    sort of. 2 pipe in some ways is more forgiving in sizing. you can undersize the boiler somewhat compared to the connected edr and have it still heat the whole system, in fact everything will be much happier with a slightly undersized boiler because it will never build appreciable pressure.

    as for the op, you're going to have a rough time until you at least put the correct controls on the boiler and ideally use the right size boiler.

    it isn't like the return trap and vapor valves on the radiators weren't there when the salesperson looked at it.

  • mattmia2
    mattmia2 Member Posts: 16,739
    edited 3:18AM

    what boiler was there before? you need to make sure things that need to be below the water line are still below the water line with the new boiler.