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Main Vents and Pressuretrol manual

1psi Member Posts: 4
We have a small one pipe steam heat system with 6 radiators. The main steam pipes have been professionally wrapped by a contractor due to asbestos, the smaller return pipes have no asbestos. The cut off pressure on our Pressuretrol is at 2 psi and I like to lower this. Once I do this the boiler does start once and that's it. I do not have a manual for the pressuretrol and I could not find anything on the Honeywell website.

Question: Where can I get a manual for this device ? Picture attached of the Honeywell Pressuretrol.

The main vents have been installed at the return lines close to the boiler. I just replaced the old ones that did not work with 2 air vents that I bought at Home Depot (Durst Corp., A883 Little Wonder). I read a lot about the Gorton valves.

Question: Would it be better to replace the Home Depot stuff with Gorton valves #1 ? Also, would it make sense to install additional air vents in the return pipes ? The main steam headers have been professionally wrapped since there was asbestos. 3 pictures attached showing the boiler, main vents and sketch.

Thanks to and Dan for providing a great source of information about steam systems.


  • Pressuretrol info

    This link will take you to the Honeywell site, I don't know if this is the exact model you have but it's probably close. Copy and paste it into your browser -

    What is the little white knob inside the pressuretrol set to? It should be set at 1. Also these controls are notoriously flaky, you would be better off with a Vaporstat and a mercury bulb one at that.

    I have included a pdf for the PA404
  • jpf321
    jpf321 Member Posts: 1,567
    your boiler piping ...

    your piping looks too small and is done in copper which is not normally the best idea. can you take 1 picture from the front and other side of the boiler piping .. and also tell us the brand and model of the boiler ..

    in terms of the pressuretrol .. there's not much too them .. shut off your electrical power to boiler, open up pressuretrol and turn the little white dial inside to "1" facing front .. then put the cover back on and turn the screw on the top until the little indicator is at the bottom "0.5" .... turn your electricity back on.. done

    in terms of the vents .. i have a feeling that those vents will work for a season or two .. then you can replace them with gorton #1's or something ... are all the steam pipes in copper? what size are they throughout basement?
    1-pipe Homeowner - Queens, NYC

    NEW: SlantFin Intrepid TR-30 + Tankless + Riello 40-F5 @ 0.85gph | OLD: Fitzgibbons 402 boiler + Beckett "SR" Oil Gun @ 1.75gph

    installed: 0-20oz/si gauge | vaporstat | hour-meter | gortons on all rads | 1pc G#2 + 1pc G#1 on each of 2 mains

    Connected EDR load: 371 sf venting load: 2.95cfm vent capacity: 4.62cfm
    my NEW system pics | my OLD system pics
  • 1psi
    1psi Member Posts: 4
    Re: Pressuretrol info

    Thanks bobc47 ... the manual and link was very helpful. Yes it's flimsy, when I set the cut out all the way down to the lowest setting the spring assembly disconnected and I had to latch it in the bottom piece and connect the screw, then changed the dial to 1. The cut out is now at around 1.5 psi. Thank you for your help.

    I guess I will look into the Vaporstat in the next few weeks.
  • JStar
    JStar Member Posts: 2,752
    edited March 2010

    Once I do this the boiler does start once and that's it.

    This has happened to me once before. The systems had no main line vents, and I believe the pressure was not going down fast enough because not enough air was being let back into the system. So the pressuretrol stayed open for hours.

    Do you hear the main vents hissing when the boiler first starts to steam up? Have you cleaned the pigtail? Can you open the skim tap or take one of the vents off to see if you break that pressure hold?
  • 1psi
    1psi Member Posts: 4
    Boiler pictures

    Thank you jpf321. Please see the boiler pictures from the front and the back. The pipe is 2-1/4" OD pipe, the copper tubing is 2" OD of the supply. The drain pipe is 1-3/4" OD and the copper tubing 1-1/4" OD. The copper is only right at the boiler, from there it goes to the pipe that was already there.

    The boiler is a Crown boiler, type BSI 138 SNF ZZ PSU.

    Today I ordered 2 pieces Gorton #1 from Pex Supply. I will install them with the Home Depot vales and see how it works.
  • 1psi
    1psi Member Posts: 4
    Main vents

    Yes I agree JStar ... I guess due to the clogged old vents the pressure relief was bad. The new vents start hissing when the boiler starts. Also, with the new vents I was able to reduce the cut off pressure to around 1.5 psi, before it was around 2 psi or more. The old valves were Hoffman Specialty Ventor # 45, but they are brown inside and nothing happens when you shake them. So I just tried the Home Depot ones but also ordered 2 pieces Gorton #1 valves today and will install them with the Home Depot ones. Thanks.
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