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Zone valve very close to rad- will it be too noisy?

spudwrench2 Member Posts: 15
(Hot water, 2 pipe direct return system with panel rads) I've got a room that runs a little hot. (Rad was oversized from the get go, then I made things worse by remodeling and insulating the room.) I blocked off the top of the rad with aluminum foil and have the manual valve throttled down pretty hard. Much better now, but still runs a couple of degrees hotter than the rest of the house, especially when two people are sleeping in the room.

I don't like the idea of TRVs. Sensor head way to close to the rad to get a really good read on room temp, the remote ones use that capillary tube thing which seems fragile and unsightly, etc. Maybe I'm wrong, but I'm also stubborn. :-)

My plan is to add a single zone valve to the pipes going to this rad, another thermostat and transformer. It won't be piped or wired so it will be able to call for heat, but the zone valve will be open when the temp in the room is below the room's t-stat set point and closed when it's above it. Sort of an electronic, bang on/off TRV.

Will one of those cheap Bluefin zone valves be noisy or unreliable? I can go for a Taco 570 if need be but they are kind of expensive. The valve is going to be located directly underneath the rad in the basement, so I'm concerned that a motorized valve might be a bit loud. Any recommendations? Is this a silly idea?


  • dopey27177
    dopey27177 Member Posts: 885
    Need to use a slow operating motor on the valve.

  • Mad Dog_2
    Mad Dog_2 Member Posts: 3,885
    Yes. I agree Mr Myron, And never try to save a buck on Plumbing and heating materials.  It rarely works out.  Taco is a great product and company. Mad Dog 🐕 
  • hot_rod
    hot_rod Member Posts: 18,195
    It’s the spring return that makes the noise, the are quiet when motoring open.
    A thermal actuated ZV would be silent, theses are low current draw versions.

    Rethink the TRV. TRV would work just fine, it’s a non electric proportional control, much nice way to control instead of bang/ bang. There are millions in use around the world.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Mad Dog_2mattmia2
  • kcopp
    kcopp Member Posts: 4,090
    have you tried a trv? before going to all the trouble of a ZV I would at least give that a go.
    They also make remote TRV... https://www.supplyhouse.com/Honeywell-Home-T104F1512-High-Capacity-Thermostatic-Radiator-Actuator-Remote-Sensor

    Im sure you can find one that fits.
  • Mad Dog_2
    Mad Dog_2 Member Posts: 3,885
    I'm a big Fan of Tunstall/Macon controls
    TRVs...high quality, very fair price, yiu can talk to the owner,, Woody great guy, made in USA!  Win win!   Danfoss is great as well but I'm always going with USA when I can.  Mad 🐕 Dog. 
  • Peakedtoosoon
    Peakedtoosoon Member Posts: 59
    TRVs are installed everywhere, on modern systems. Mount it on the horizontal, and it'll be fine.
  • spudwrench2
    spudwrench2 Member Posts: 15
    That Caleffi zone valve with the unions is great idea. I don't trust myself 100% to sweat a zone valve w/o cooking the guts, so I was planning to disassemble whatever I installed before sweating it. Unions are a much more elegant way to isolate it w/o having to strip down the valve.

    I'll think some more about TRVs, but the rad is mounted on an outside wall. A TRV with a local sensing head is going to be 6" or so from the rad- how can that be a good read of the room temp? Would you install a regular thermostat that close to a rad? The TRVs with the remote sensor would need a quite a long tube to reach an inside wall due to the layout of the room. I know the Europeans love them, but I just can't do it.

  • hot_rod
    hot_rod Member Posts: 18,195
    Press tailpieces are available on all the zone valves.

    TRVs have threaded and copper compression options!

    Eye level isn’t ideal for thermostats either, if you sit or are in bed the majority of the time in your home.

    There was a movement years ago to lower thermostats but it is the convience of eye level over the function that wins
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mattmia2
    mattmia2 Member Posts: 7,150
    You could use a trv type valve and a heat motor actuator, those are mostly silent.

    You can pick a threaded valve then you can sweat on adapters and screw in to the valve body. Or the numerous options @hot_rod mentioned.