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Replace Gorton 1 main vents

Stream gurus,
Thanks for help this past summer.  I'm wondering if my main vents are operating correctly or need to be replaced.

 I have a Weil McClain boiler installed in the mid 70s.  I did a couple of maintenance projects this summer including insulating the two mains, fixing a dripping wet return, and adding a flush valve to the bottom of the sight glass.  I also recorded all the vent makes and models on the radiators and mains. 

 I know y'all have told me the boiler is piped poorly from previous posts.  But with that as the context can you tell me if the Gorton no 1 vents at the end of the dry returns (shown in picture) should be replaced or are they operating correctly? They've been there for the 16 years I've been in the house btw.  Though I read TLAOSH, I have no idea if they should be at the end of these dry returns or really at the distal end of the mains.  

I fired up the system for the first time today.  As the boiler water came up to temperature and I felt the header and mains getting hot I figured I should feel air rushing out of the Gorton no 1's, but no air discharge was felt. Also i felt the first floor radiators getting warm before the end of the dry returns y the boiler getting warm.  I thought that if these main vents were operating correctly that is feel them vent and warm up before any radiators.   

Are those Gorton no1's behaving correctly?
Am I understanding the operation correctly? 
Any additional corrections besides the near boiler piping? 
What should I be asking?


  • Steamhead
    Steamhead Member Posts: 16,282
    How long are your steam mains, and what pipe size?

    What model Weil-Mclain?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • mjgordon
    mjgordon Member Posts: 15
    Two 2" mains about 20' long each.  1.25" Dry returns on each main the same length.   Oil fired Weil McLain model unknown as name plate is too hard for me to read.  Photo of boiler name plate and burner attached. . maybe you'll have better luck
  • Steamhead
    Steamhead Member Posts: 16,282
    It's a W-M 6-65, a "65" series boiler with 6 sections.

    Given its capacity and the main lengths and sizes, those Gorton #1 vents should be OK.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Jamie Hall
    Jamie Hall Member Posts: 21,568
    And if those really are dry returns -- and not extensions of the steam mains -- they shouldn't get hot. In fact, they should never see steam at all. But if they are extensions of the steam mains, then eventually they should get hot.

    That said, it's surprisingly hard to feel air coming our of a main vent, even if it's working properly, unless it's much too small. So not to worry about that.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • gfrbrookline
    gfrbrookline Member Posts: 727
    edited October 2021
    Based on 20' of 2" main and 20' of 1 1/4" return you have .66cfm to vent. According to the Gerry Gill chart the G1 at 2oz. vents at .54cfm so your venting capacity is roughly 20% less than what you need. You might benefit by adding a T and another G1 to each main, it is marginal but the system will breath better. It is also short money if you do it yourself.
    EBEBRATT-Ed Member Posts: 13,847

    If your NOT building pressure on your low pressure gauge your vents are probably large enough as long as it heats the radiators evenly.

    If you building pressure you may want more venting
  • dopey27177
    dopey27177 Member Posts: 887
    The boiler equalizer piping should be no less than 1 1/2 " pipe.
    As far as the Gorton #1 vents go I would remove them and and soak them in vinegar and give them a good shake to assure that any debris is removed out of the vent valve. If they then do not work replace them with new #1s.