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motorized valves

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x19dave
x19dave Member Posts: 7
edited January 19 in Gas Heating

Hi, my motorized valves pass water when closed, and the outgoing pipe is hot

Is this normal for central heating motorized valves, or are they just old and worn

thanks

dave

Comments

  • Intplm.
    Intplm. Member Posts: 2,906

    Please post the name and model number of the valve you are referring to.

  • hot_rod
    hot_rod Member Posts: 27,054

    A pic of the valve and boiler piping would help. Has it held tightly in the past? Any changes to the system, a pump switch perhaps?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • x19dave
    x19dave Member Posts: 7

    Okay will get some pictures tomorrow it has always passed but I have o ly been in the house 3 years and I think the system is over 10 years old

  • x19dave
    x19dave Member Posts: 7

    The only changes i have done is replaced some radiators

    Dave

  • hot_rod
    hot_rod Member Posts: 27,054

    Many of the spring return valves like Honeywell, Erie, White Rogers, have a rubber ball or flapper as the shutoff. These can deteriorate over time and allow some leakage.

    Or the return spring could break.

    So they held for the previous 2 heating seasons?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • x19dave
    x19dave Member Posts: 7

    A far as I know from.checking they have always passed but I think it has got worse

  • x19dave
    x19dave Member Posts: 7

    Please see photos anything else just ask

    2026-01-1811.15.143704718878918439052.jpg
    2026-01-1811.15.302265405415730907946.jpg
    2026-01-1811.15.555976305694194178988.jpg
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,747
    edited January 18

    That is an old design with inverted flare connections. I believe the repair part for that valve is still available. 40003918-006 repair part

    I find it interesting that you have 240 volt motors to operate those valves.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • x19dave
    x19dave Member Posts: 7

    So do you think the valves had had it should they stop all.flow or does some.bypass

    TThanks

  • hot_rod
    hot_rod Member Posts: 27,054

    where are you located? A 25-80 union body pump is not common in the US, and 240v is not common. It looks like Euro based components?

    25-80 the 80 is head in decimeter which converts to 26’ or about 11psi

    Those zone valved have an 8 psi shut off. It’s possible the circ is pushing them open a bit? Looks like a 2015 vintage valve.

    Take the cover off and see if someone disconnected one of the two springs, that reduces the shutoff even lower

    If it has always bypassed, perhaps there is a pressure bypass in the piping that is mis adjusted, or the rubber ball inside is damaged.

    a rebuild may or may not solve the problem. The least expensive first try is to pull the zone valve apart and inspect

    A few more piping pics would maybe show if you have a PAB bypass valve

    A delta P circulator would be a nice upgrade to avoid overpumping and save some electrical costs

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • x19dave
    x19dave Member Posts: 7

    Hi yes i am in the UK 7 the bypass is shut

    And there should be two springs sure there is only one

    When you say they have an 8psi shut off does that mean they need more than 8 psi to get the ball to seat correctly

    Thanks

    Dave

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