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Thermostatically controlled radiator valve.

tp tunstall
tp tunstall Member Posts: 63
check out www.maconcontrols.com
use the pull down sheet under one pipe steam
in addition, under dan's "library" is an excellent article by danfoss regarding application etc. t.p. tunstall


  • Rob_40
    Rob_40 Member Posts: 55
    Thermostatically controlled radiator valve

    I have a single pipe steam heat system on my home. Looks like it was a coal boiler converted to gas. Two stories plus an unheated attic. Living room, dining room and kitchen on first floor. Three bedrooms and a bath on the second floor. Each room with a single radiator. Thermostat is on the first floor. The problem is the difference in warmth between first and second floor. Second floor gets much warmer. I suspect that its due to the heat rising from the first floor adding to the heat from the second floor radiators and the thermostat on the first floor doesnt detect it. I lower the thermostat, and the first floor is too cold. House walls I suspect are uninsulated. Roof is insulated.

    Now my question: I thought I read somewhere about having a thermostat on each radiator to control the temperature in each room. I have tried to find that information, but without luck. I've read Holohan's "Lost Art" chapters on the single pipe system. I would imagine that if there were such individual controls for a radiator, he would have mentioned them in his book. I can see how adjusting the second floor venting is part of the solution. Is there such a thing as a temperature adjustable vent. Maybe it controls the steam valve. I dont know.

    I appreciate in advance anybody taking the time to read this and respond.

  • wsdave
    wsdave Member Posts: 97

    Try here:

    I have three floors and I'm using the Honeywell-Braukmann brand and they work great.


  • Brad White_9
    Brad White_9 Member Posts: 2,440
    One Pipe Steam TRV's

    are the ticket. The one's I specify are Macon Controls and Danfoss. There is another, Ammarc, if I even came close to spelling it correctly, that shows up as a substitution now and again.

    The key feature these have over the others is that there is an integral vacuum breaker. It is not enough just to hold back air release to hold back steam, but rather you have to also allow the vacuum release to get the condensate out before the next cycle.

    If Honeywell-Braukmann has an integral vacuum breaker, this is the first I have heard of it. They very well may by now. H-B does make a good valve in general, so no slight meant towards them.

    My $0.02

  • wsdave
    wsdave Member Posts: 97

    Hi Brad,

    I too was concerned that the H-B TRVs that I use came with the Hoffman 41 steam vent however, they seem to work just fine on the 3 radiators I have them installed on.
    I too looked into Danfoss but couldn't find one, until yesterday, when I came across the RA2000.
    I may purchase one to try.
    As I haven't used these I cannot comment but defer to your expertise.

  • Brad White_9
    Brad White_9 Member Posts: 2,440

    For years, I too specified any number of TRV's for one-pipe steam using brands that were very good for hot water. Any problems I had were transient and that was due to my not fully understanding the entirety. Seems so obvious now :)

    Macon TRV's are my default specification base. They and Danfoss "get it". Both are excellent; Macon is locally imported and the service is excellent. Again, nothing against the other brands. My preference.

    Essentially the "hold-back" problem comes when the room is at or warmer than setpoint (TRV is closed to the airvent) and the boiler is off or down-cycled. No vacuum relief and the condensate misses an opportunity to take the shuttle home.

    When the TRV opens and the system might be under pressure (again, higher pressure than it should have been in my ignorance) the sudden release of the air vent, cold in the moment, let the condensate out (finger off the soda-straw and all that). Gurgling, sloshing and banging would occur, especially if a good charge of condensate had collected.

    Not a horrible problem but I judge a system by it's most obvious flaw, so the vacuum breaker is my new standard. Seems to be catching on.

    My experience is hardly the last word though, far from it. I would dever to the installers and service contractors more on the front lines than I am. Thanks for weighing in!

  • Dmitri_2
    Dmitri_2 Member Posts: 11

  • wsdave
    wsdave Member Posts: 97

    I see what you are saying now and it makes sense to this hard head!

    I'm looking at the Macon - trying to find a distributor.
    Thanks again
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