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Main vent location

Is there a major difference in efficiency between having the main vent on a single pipe steam system at the end of the main run as opposed to at the end of the return (tapped right where the return drops to a wet return/hartford loop next to the boiler)? I mean other than the added volume of air to vent in the return. Will the lower tap height in regards to the end of the main make any difference?

The "emergency" new boiler install 2 winters ago reset my checking account to 0 like I just lost in Pac Man. Now I can finally do something about it if it's not ideal.

Thanks for any insight


    JUGHNE Member Posts: 11,021
    Often the determining factor is where they might be installed with the least pipe work. IMO
    End of steam main is best.
    But end of dry return might be easier.
    This will turn the return into a steam main, giving off heat if not insulated....maybe good maybe not.
    Once the air is past the last takeoff riser, the steam is where it needs to be. The added time to vent the return does not affect the operation of the steam distribution as it is where it would be in either installation IMO.

    How about pictures of your boiler piping, floor to ceiling and also the end of the mains?
    And how long and size of mains?
  • ReluctantDIYer
    ReluctantDIYer Member Posts: 4
    The decision to place the vent at the end of the return was exactly "less effort," for sure. I was left with a single Gorton 1, which I've since (sloppily) changed to 2x Gorton 1s since it was cheap and easy. I have a single main made of 2" pipe that's about 46' long.

    As for pics , I've attached 2. The first shows the end of the main and the other shows the end of the return with a homemade 2 vent antler where I replaced the single vent.
  • Fred
    Fred Member Posts: 8,542
    With a 46' main, you probably need another Gorton #2 or a Big Mouth to vent that main. Also, it is questionable as to the location of the vents. Being that close to or maybe even at the boiler water line, those vents likely aren't doing much. They should be mounted up on the main or before the vertical drop on the return. Is that lower horizontal return above the boiler water line? If so, by how much?
  • ReluctantDIYer
    ReluctantDIYer Member Posts: 4
    The end of the dry return where the main vents are tapped is approximately 2' above the water line. But then the vents sit atop a 3' riser (forgive me for any incorrect terminology)
  • neilc
    neilc Member Posts: 2,667
    "2' above the water line"
    what does your boiler pressure get up to before the Ptrol shuts it off?
    at 1and 1/2 psi you're borderline with pressure backing water up to that 2 ft height, which would then close that vent port to additional air from the main
    known to beat dead horses
  • Gsmith
    Gsmith Member Posts: 431
    Your best bet is to move the vent to the end of the steam mains, not on the dry return, since the level is so close to the boiler water line.
    JUGHNE Member Posts: 11,021
    Have you looked for any plugged tees at the end of the main?