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TRVs - Single Pipe Steam

marius Member Posts: 4
Hi gang,
Can anyone recommend an affordable reliable thermostatic radiator valve or where to buy one? Also thoughts on the wax/chemical version vs. the electric version would be helpful. I saw one in DH's book "The Greening of Steam" that allows you to set the temperature in the room but there is now brand name in the book or information on where to purchase it. Thanks !


  • Paul48
    Paul48 Member Posts: 4,470
    Any of them will allow you to set the room temperature. That is their purpose. There's a few manufacturers, and the quality is about the same. About the only difference is that some come with a vacuum breaker included, or integral and others you have to purchase it separately. I believe Danfoss makes one that includes a vacuum breaker. None are cheap, but that is in direct proportion to the depth of your pockets. has them.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,492
    Are you experiencing some hot spots in your house? The solution may likely be found in balancing the system. TRV's are often used as a sort of bandaid to rectify sysmptoms, instead of causes.
    Describe your system, and its problems, and we will try to help.--NBC
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,344
    You can get those from our friends at Tunstall:

    Good people to do business with!
    Retired and loving it.
  • Scott.Malo
    Scott.Malo Member Posts: 19
    Hi Marius - Please feel free to call our main number at 800-423-5578 and ask for Scott or Woody. Or, if email is easier for you, please email me at [email protected] I would be happy to help you!
  • Scott.Malo
    Scott.Malo Member Posts: 19
    Also - Just to address the above comments, our 1-pipe steam valves come with vacuum breaker and the non-electric thermostats have a wax sensor and work great. They will also help balance your system as instead of just overheating radiators all the time, once a radiator is satisfied based on the set point of the thermostat, the steam will then travel to other radiators more efficiently.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,492
    They are great to use after all other attempts at balancing have been completed. Some people asking for advice here have found their radiators still heating up when the radiator vent was closed off, as a result of overpressure. In such a case the TRV will not be able to cope.
    To test the possibility, turn the radiator vent upside down, and see if the radiator stops heating. This mimics the TRV in stopping the escape of air.--NBC
  • marius
    marius Member Posts: 4
    Thank you all for your input.
    The system is pretty well balanced as it is... of 15 radiators pretty much all are tamped down to some degree.
    The reason for looking into TRVs is that pretty much all of the rooms in the house have radiators with one thermostat controlling them all in a downstairs hallway. However, half of the rooms have radiant heat in the floor, each room with it's own thermostat for the floor. I figure the TRVs can help balance the rooms with both radiant and radiators in the same room to establish balanced heat in the room.
    I greatly appreciate all feed back.

    To switch subjects, the single pipe steam system we have seems to be adding water. Our automatic water feed seems to be adding water to the boiler, audibly, and visually verifiable via the water column, when the boiler is both on and off.

    Has anyone had any trouble/experience with the bellow water feeder? My guess is that it is either defective, wired incorrectly (although it does function correctly when the low water cut off calls for water) or there is a scrap of something caught in the solenoid valve.

    Thanks again!

  • Jamie Hall
    Jamie Hall Member Posts: 16,332
    The water feeder question might have been better separate...

    That said, the real question is: does it over fill the boiler? If it does, then it (or the level control controlling it, which is separate) is malfunctioning. Perhaps a stuck solenoid, stuck switch, gremlin... However, if it is not over filling, then that's normal. Some of that type of feeder are set up with a time delay on feed, to allow for slow returns, and can and do feed some time after the boiler shuts off.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChrisJ
    ChrisJ Member Posts: 11,793
    That drafthood seems way too close to the top of the boiler.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • marius
    marius Member Posts: 4
    Jamie, yeah it is overfilling the boiler and the lwco is not even calling for it...

    Chris I've heard that about the draft hood before but haven't taken care if yet.. I heard it's bc it pulls too much heat from the system and so is wasteful..
    EBEBRATT-Ed Member Posts: 9,408
    Check the boiler mfg specs on the draft hood. @ChrisJ is correct it needs to be installed at the correct height.

    Sounds like the feeder needs cleaning or replacement. Do you really need a feeder? They can be problematic
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,492
    The problem with such a system of two sources of heat is that the rooms without the additional radiant heat will need to get enough steam to be comfortable. This will require that the thermostat, (perhaps wrongly located in a hallway), fire the steam system when the steam heated rooms are cold, and not be satisfied by the radiant system.
    Perhaps you could set the radiant system thermostats down, and get the steam portion balanced with the thermostat sensor moved to one of the cold rooms of the house.
    I am guessing the radiant was added later as a bandaid for an unbalanced/Brady-vented system.--NBC