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Macon Controls 1PS TRV and electrical actuator?

I've been using a Danfoss TRV for my one-pipe steam radiators for the last few seasons and they tend to work OK to keep the living room and two bedrooms in my NYC apartment from overheating (before I installed them we were broiling pretty much throughout the entire heating season). However I find that I can't always keep each TRV set to the same temperature, sometimes I need to manually turn the TRV setpoints up or down depending on time of day and how cold it is outside. That becomes tedious.

I noticed on the Macon Controls website, it states their one-pipe steam TRV can be controlled by some of their electrical actuators. Can anyone explain how this might work? Thanks in advance.


  • EBEBRATT-EdEBEBRATT-Ed Posts: 6,116Member
    Call Tunstall. I see you have been on their site. You would have to remove the actuator and install a 24 volt electric actuator, install a thermostat and wiring. Not sure you want to do that.

    No matter whose trv you use their are failures. Make sure you have the correct valve and actuator for your application
  • KC_JonesKC_Jones Posts: 4,281Member
    I don't know how your system works, but with an apartment things won't be perfect. The TRV can't fire the boiler. So if the TRV is closed because the room is fine, then the room falls and it opens, but the boiler isn't firing it won't warm up.

    You are at the mercy of the boiler controls in this situation.

    It might not be a TRV issue.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • gennadygennady Posts: 770Member
    Using TRV in one apartment will not solve the problem. You will need to update steam system venting, steam pressure settings, controls and other components of the heating system,
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
  • Scott.MaloScott.Malo Posts: 14Member
    Hi Marktheknife! Scott Malo here from Tunstall Corporation and Macon Controls. All the feedback you are getting here on The Wall is applicable to your situation. The function of the 1-pipe steam valve with vacuum breaker, is to prevent overheating. When the steam condenses, it creates a vacuum. The vacuum breaker allows air back into the system which in turn, when the temperature drops below the set point of the non-electric thermostat, it allows steam back into the radiator. As gennady mentioned, there are a number of "other" variables that also need to be operating in concert with the TRV's. Boiler cycles, master venting and pressure will all affect the overall system performance. 1-Pipe steam valves are designed to operate on very low pressures and if that is being adjusted frequently it can cause issues. To answer your question, yes, you can use an electric thermostat on a 1-pipe steam valve but as EBEBratt mentioned, you would need to wire that and that can get complicated.
  • JohnNYJohnNY Posts: 2,372Member
    I do stuff like this for buildings all year long in Manhattan and Brooklyn. In some cases, the system has been altered over the years in such ways that you'll never quite get the temperatures right all the time, but you can get pretty close. TRVs are a good tool to help get you into the vicinity of a satisfactory condition but you should expect some degree of inaccuracy and trial-and-error when using them. I like Macon for their vacuum breaker option and client support, so in my opinion, you're on the right path, but there's no substitute for a good field technician as a first step to restoring/preserving your sanity.
    For installations, troubleshooting, and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is the Boilers and Hydronic Heating Systems Course Instructor at NYC's Mechanics Institute, a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
    John also oversees mechanical installations and maintenance for metro-area clients with his family's company, Gateway Plumbing and Heating along with his brother/business partner.
  • marktheknifemarktheknife Posts: 7Member
    Thanks, everyone, for your input.

    I'm aware of the limitations of a TRV on an individual room radiator when I have no control over the boiler itself, and I'd be willing to bet there are other issues that are affecting my building's entire steam system that should be addressed separately. One problem is that I can do what I want in my own apartment, I can't necessarily convince the board of my co-op to invest in an audit of the building's steam heat system.

    Before I installed TRVs on several of the radiators in my apartment, we were usually roasting throughout the entire heating season. We live on the first floor, people on the top floors tend to complain that it's too cold. So the TRVs have definitely helped.

    What I'm finding is that on some days, if the TRV in one room is set to, let's say, "3," the room may still get too hot. Closing the TRV will help keep the radiator from heating up with the next boiler cycle, allowing the room to cool off. But if we don't remember to open the valve back up, the room may end up getting too cold later in the evening when the outside temperature has dropped.

    So what I'm looking to do is connect some kind of room thermostat to the TRV so that changes like this can either be scheduled, or at least controlled remotely without having to manually turn the dial in the room (e.g. if I used a wifi thermostat with a mobile app).

    At this point, I'm not sure what would require more effort; connecting a new valve with electrical actuator and wiring it to a thermostat (three or four times over for each radiator with a TRV), or convincing the co-op board that they should get the building's steam system tuned up with someone that knows what they're doing (I suspect the plumbing company that typically deals with our boiler does not actually fit that description).
  • LarryKLarryK Posts: 45Member
    edited October 2017
    I'm a homeowner with one pipe steam and there is one room that gets a lot of sun in the day and a lot of heat loss when there is no sun, so the heating requirement varies a lot during the day. I installed a remote bulb TRV and it helps, but the problem is that even after it closes it has no effect until the next heating cycle. I have been thinking of what I could do to fill the radiator with air. If I had the the electrically actuated TRV could I connect it to an aquarium pump and a time delay to pump air into the radiator and stop the steam immediately? My system works at something like 0.2 psi.
  • EBEBRATT-EdEBEBRATT-Ed Posts: 6,116Member
    @LarryK When the room temp is above the set point on the TRV the actuator on the valve should shut and not allow steam into the radiator (or close the vent) if it's one pipe.

    If the radiator is heating when it shouldn't then you have an issue. I don't think your aquarium pump will work
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