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One pipe radiator system

coophil Member Posts: 2
edited November 2021 in Strictly Steam
Hey, first time on here… I have a one pipe radiator system and I’m trying to take a radiator out of my bathroom so I can redo the finishes and then reinstall.  I’m trying to figure out if I need new valves or not but can’t identify or understand what I think is the locksheild valve.  I’m assuming it is used to balance the system and i have been able to shut the flow off completely and turn it back on but it is screw controlled and will spin continuously in either direction.  Is it supposed to work like this?  Has anyone seen one like this before?  If I need to replace it what should I replace it with?  Thanks in advance!  


  • KC_Jones
    KC_Jones Member Posts: 5,736
    Several things to unpack there.

    Looks like a copper pipe feeding the valve which indicates the system has been messed with already.  What size is the feed pipe, and is it indeed copper?  I ask because too small of a pipe can cause issues.

    The valves on one pipe steam should either be fully open or fully closed, they are not used to regulate the heat.

    For me, if the valve isn’t leaking, the unit heats, there isn’t any banging or other noise, I’d just keep it as is.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Ironman
    Ironman Member Posts: 7,373
    edited November 2021
    As KC said, the valve on a one pipe system must be left fully open or fully closed - no throttling. It will trap condensate in the radiator if it’s throttled. That will result in banging and poor performance.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    JUGHNE Member Posts: 11,060
    What does the other end of the radiator look like?
  • retiredguy
    retiredguy Member Posts: 902
    When you said 1 pipe system do you mean steam or mono-flo water? Need a picture of the other end and maybe the whole radiator.
    EBEBRATT-Ed Member Posts: 15,513
    Are you sure there is only one pipe to the radiator?
  • coophil
    coophil Member Posts: 2
    The system is not steam it is hot water and it is copper.  The attached diagram is what I mean by a one pipe system.  The main pipe is copper and is 1.5”.  The other side has a shut off valve see photo.  The system works great and I don’t want to mess with it just need to take the radiator out while I remodel the bathroom, and then put it back in when I’m done.  But want to be prepared if one of the valves quits working.
    EBEBRATT-Ed Member Posts: 15,513
    edited November 2021

    Now we can see what you have.

    The side of the radiator that has the valve with the handle (left side) you can shut that off. There is a union connection there that you can unscrew.

    The other side of the radiator is a screw slot "balancing valve" that valve will not hold water pressure.

    Your going to have to drain the boiler to do this and refill it when you ate done.

    So you have two choices:

    1.Drain the system. cut the supply and return branches in the basement and install a ball valve in the supply and in the return. Shut those valves off refill the system and you will have heat. The you can work on removing and reinstalling the radiator.


    2. Drain the system and remove the radiator and live with no heat until your done.

    Either way, make sure to use some back up wrenches when you take those unions apart.

    Wipe those connections off good with a rag. Maybe use a little wd-40 to clean them up....no sanding or scraping.When you put those back together use some anti seize on the threads of the union and on the face of the union. and tighten them up.