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Very Unusual Honeywell Zone Valve Trouble

Maintek Member Posts: 7
I replaced the old cast iron boiler system (primary piping only) with a new high efficiency boiler system (primary/secondary piping).  The system had 18 Honeywell Zone Valves in the boiler room. (I know this a purge system)


Now the Honeywell zone valves open electrically, (the spring stretches) but sometimes the water does not start to flow.  At first I thought I had air locks, but then I realized that the ball is apparently not moving to the open position.  If I just move the manual lever back and forth once the pipe heats up immediately.  This problem seems somewhat random as to when and which zone.  I replaced one of the valves and the new valve did the same thing.

It seems to have to do with the pumping, pressure differentials, etc.  I have had problems with pump sizing and Honeywell, but always they couldn't close against the pump.  Flow is in the correct direction.



  • Mark Eatherton
    Mark Eatherton Member Posts: 5,839
    Replace it again… They don't make 'em like they used to.

    Just kidding!

    Sounds like a wiring issue to me. If the valves manual opener had spring tension on it when you actuated it, the valve is not open. If there is no resistance, that indicates the valve is open, and you still don't get a call for heat, its either a bad end switch, or bad wiring.

    Grab your DMM and start looking for bad connections…

    Also, if you are opening valves from the closed position (bypass) with a pump, you either need to double check your pump sizing, or install a pressure activated bypass to relieve the excess head pressure. That is NOT a normal consideration.

    It's not too late to get signed up for the College of Hydronic Knowledge class sponsored by the RPA and presented by Dave Yates… :-)

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • HDE_2
    HDE_2 Member Posts: 140
    check your power supply

    If you have 18 zone valves still, check your VA rating of the transformers

    It can take 180 to 200 VA of a 24V system to open all those valves fully

    Since a standard transformer is 40 VA with a suggested max of 4, maybe 5 H/W zone valves, are you coming up short?
  • hot_rod
    hot_rod Member Posts: 16,272
    what else changed

    when the boiler was replaced? Pump size or location, wiring or power source for the ZVs?

    Do you know for a fact all the ZVs operated before the changeout?

    It could be you have some failed end switches? Don't know what vintage valve you have, as I recall early models would not make the end switch when the lever was moved manually. So possibly another valve has called the pump on?

    Actuator motors can fail, the gear train can strip, need to check each valve carefully for connections and motor, switch condition.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Maintek
    Maintek Member Posts: 7

    We tried solving it with the wiring.  First off no end switches.  The zone valves open (no spring tension)  but no flow (pipe not hot).  If I move the zone valve lever a little bit the pipe heats right up.  We have a variable speed Wilo pump.  Which was installed after the boilers were replaced.  This problem seems to be something to do with the pressure differential that the zone valves see. 
  • JStar
    JStar Member Posts: 2,752
    Zone valve

    Maybe the rubber ball melted while soldering. You can also take the control head off of the body and see if it moves freely when not attached to anything.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,839
    edited January 2014
    Piped backwards?

    If you have any HAMMERING when a zone closes, the valves are installed backwards. Generally speaking, these valves open against flow. If installed so it open with the flow, the pump pressure may be capable of not allowing the ball to come off of the seat. When you use the manual lever, you are unseating the valve, and allowing flow.

    The valve has a directional arrow on the side of the valve. Make sure its going in the right direction. Also, check your pump. It may not be going in the right direction.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • unclejohn
    unclejohn Member Posts: 1,757
    Are you saying

    That once you open it manually it stays open? If so you may not have a big enough transformer to power open all the zones which would account for the randomness of the issue.
  • Maintek
    Maintek Member Posts: 7
    Zone valve trouble

    Manually open without power the zone valves will stay open, but with power they appear to operate normally, but don't open up occasionally without touching the lever.  We thought of the transformers too, so we went to 75VA transformers, but the problem persists.
  • JosephTonozzi
    JosephTonozzi Member Posts: 5
    The Honeywell zone valves were made in Canada before I’ve seen them still working from 20 to 25 years old . I put them in . I remember a bad run of them in The early 90s I replaced so many for free that it motivated me to look for a better zone valve . And the ones I’ve seen lately made over in Hungary seems to be 1 out of three not very good . The brass gear is about as thick as a tin can . If you do not push the manual lever slowly it skips on the gear . Lately I’ve seen a lot of the systems with Honeywell letting flow by when in the closed position . The last two jobs they were actually on the supply side of the system ?? Why would one choose this . My best solution for fixing a Honeywell zone vale is to throw them in the scrap pile . Thermal actuating valves seem to work pretty well unless your in a hurry to go home while waiting to check their operation . I’m pretty impressed with the new Taco Sentury zone valves they are actually a ball valve with a motor . And with the electrical Capacitator you can run 12 to 14 off of one 40 va transformer . I have over 60 of the Tacos out there now so far so good . My only concern with the taco would be if not exercised and depending on water quality if the ball will get seized up . Haven’t had any issues yet . To bad the majority of the zone valves you see out there are the Honeywell . Keeps us service guys from being like the lonely MAYTAG MAN. Not saying all Honeywell stuff is bad we depend on them for a lot of controlling of our equipment . I just would not recommend using them on Space X .
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,687
    @JosephTonozzi Curious as to why you responded to an 8 year old thread?