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Taco Zone Sentry Zone Valve not turning

We have a 12 unit apartment building with hot water heat that we provide. We upgraded the heating system almost 4 years ago and installed 14 Taco Zone Sentry Zone Valve Z075C2-1 for the apartments and other needs.

We've had 4 head go bad over the 4 years, 2 just failed and a replacement head solved the problem. The 2 that failed in the last month broke the tab for the manual control due to a build up of sediments on the ball valve making them very hard to turn. Replacing the head on each obviously didn't solve the problem and the valves didn't fully close with the new heads. We've replaced the 2 zone valves (complete replacement) but are wondering of others have had similar problems with the Taco Valves?

We've had the old style zone valves in the same building for the past 40 years and nary a problem through the years. These don't seem to be built strong enough to overcome the least bit of resistance (there's very little build up of minerals on the ball) .

Does Taco make a bigger, better valve? Should we filter the water to the boiler? Any help is greatly appreciated.


  • hot_rod
    hot_rod Member Posts: 22,245
    Pretty much any hydronic component is at the mercy of fluid quality, it is almost impossible to design around that.

    Be sure your system is tight and not taking on fresh water. Every time you add new water you add more scaling minerals unless you de-mineralize it.

    Any additives ever added?

    You could sample the water, sent it to Rhomar or Fernox for analysis.

    Flapper type or thermal actuators are a bit less sensitive to bad fluid, less tight tolerances.

    Best to check and "fix" the fluid, as it is scaling boiler and heat exchange surfaces also.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • ChasMan
    ChasMan Member Posts: 462
    edited January 2018
    Zone Sentry.. Good idea but not working well. It appears that it suffers from the 10 in 5 syndrome where they tried to put 10 pounds of efficiency in a five pound bag. The motor doesn't have a closing spring and relies on a tiny amount of electricity to close the valve. They don't even work in the best of conditions. I had two fail in a week.Taco does warranty them. I have a feeling there is too much fluff in a heating job where throwing them in the garbage is easier than returning them. I like the Caleffi Z one the best. While not perfect, it hit the notes I require out of a zone valve. Strong, Positive shutoff, slow closing, reliable, good end switches, not too power hungry and they sweat reliably without too much fuss.
    I can deal with the upside down label which is my biggest beef and the fact that I have to keep my own spares. I like high tech but a storage capacitor needs some sort of backup.
  • Rich_49
    Rich_49 Member Posts: 2,766
    You have no valve problem . You have a water quality problem . Fix that before more valves .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    I Too like the Z-one from Caleffi, had zero problems so far. One has had an intermittent end switch but I swapped the head and used the bad end switch head in another application which didn't need an end switch. I also wet rag all valves while soldering and have not had any issues.

    I generally like Taco products, but not their zone valves.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!