Potterton MSV 322 3 way valve problem

Discussion in 'Plumbing and Central Heating' started by Wynn, 16 May 2009.

  1. Wynn

    Wynn

    Joined:
    16 May 2009
    Messages:
    8
    Thanks Received:
    0
    Location:
    Carmarthenshire
    Country:
    United Kingdom
    Hi hope someone can help? I've got a problem with my 3 way valve, I've changed it twice and both times the actuator has failed after a few months. I assume that there is a problem with the voltages going to it. I've measured the voltages and copied them below, any advice would be welcome.

    everything off

    Grey 240v
    Orange 18v
    White 90v
    Blue 0v

    Central heating only

    grey 240v
    Orange 17v
    White 240v
    Blue 0v

    Hot water only

    grey 0v
    Orange 240v
    White 8v
    Blue 0v

    Heating & Hot water

    grey 60v
    Orange 240v
    White 240v
    Blue 0v
     
  2. Sponsored Links
  3. seco services

    seco services

    Joined:
    3 Dec 2007
    Messages:
    15,701
    Thanks Received:
    1,260
    Location:
    Essex
    Country:
    United Kingdom
    half of them are wrong.

    what other controls have you programmer, cyl stat, boiler ?
     
  4. weareleeds

    weareleeds

    Joined:
    13 Dec 2005
    Messages:
    664
    Thanks Received:
    2
    Location:
    Yorkshire
    Country:
    United Kingdom
    I would be looking at spindle on valve body is it stiff
     
  5. seco services

    seco services

    Joined:
    3 Dec 2007
    Messages:
    15,701
    Thanks Received:
    1,260
    Location:
    Essex
    Country:
    United Kingdom
    so why would that give out wrong voltages ?
     
  6. D_Hailsham

    D_Hailsham

    Joined:
    18 Oct 2007
    Messages:
    10,587
    Thanks Received:
    1,344
    Location:
    Kent
    Country:
    United Kingdom
  7. Wynn

    Wynn

    Joined:
    16 May 2009
    Messages:
    8
    Thanks Received:
    0
    Location:
    Carmarthenshire
    Country:
    United Kingdom
    Hi thanks for replying, I have a Siemens RWB9 programmer, RAA02 room thermostat, Ram1 tank stat and Vailant VC GB 182 EH boiler.
     
  8. seco services

    seco services

    Joined:
    3 Dec 2007
    Messages:
    15,701
    Thanks Received:
    1,260
    Location:
    Essex
    Country:
    United Kingdom
    you say the actuator has failed.
    what happens so you know its failed ?
    you boiler won't fire up when heating called for ?
     
  9. Sponsored Links
  10. Wynn

    Wynn

    Joined:
    16 May 2009
    Messages:
    8
    Thanks Received:
    0
    Location:
    Carmarthenshire
    Country:
    United Kingdom
    Hi again, yes the boiler doesn't fire up. to be honest I've been living with this problem for years and can't remember what else I did to confirm that the actuator failed. However i do remember that first time it happened I bought a new actuator and everything was fine for a month or so. So I'm pretty sure it's that.
    thanks
    wynn
     
  11. seco services

    seco services

    Joined:
    3 Dec 2007
    Messages:
    15,701
    Thanks Received:
    1,260
    Location:
    Essex
    Country:
    United Kingdom
    do you know what is failing in the actuator ?
    motor, micro switch etc.
     
  12. Wynn

    Wynn

    Joined:
    16 May 2009
    Messages:
    8
    Thanks Received:
    0
    Location:
    Carmarthenshire
    Country:
    United Kingdom
    I believe that it's the motor
     
  13. seco services

    seco services

    Joined:
    3 Dec 2007
    Messages:
    15,701
    Thanks Received:
    1,260
    Location:
    Essex
    Country:
    United Kingdom
    that a dear expence replacing the whole actuator for a failed motor.
    so its only heating that is not firing up the boiler then ?
     
  14. Wynn

    Wynn

    Joined:
    16 May 2009
    Messages:
    8
    Thanks Received:
    0
    Location:
    Carmarthenshire
    Country:
    United Kingdom
    That's right hot water works fine, I've kept the valver in the mid position setting and rely on TRVs to control the central heating, but that's really ineffective and I want o get this sorted.
     
  15. D_Hailsham

    D_Hailsham

    Joined:
    18 Oct 2007
    Messages:
    10,587
    Thanks Received:
    1,344
    Location:
    Kent
    Country:
    United Kingdom
    The valve is not powered up for hot water only, which is why that works OK.

    Unless the valve is very old, you can separate the actuator (metal box) from the valve body and inspect/test the two parts separately.

    The spindle in the valve body should rotate easily, but not a full rotation about 20° max. If it is stiff, a small amount of WD40 or similar lubricant may help.

    As for motor, you should be able to see if it works when you put the heating on.

    If the valve is OK and the motor works we need to test the actuator.

    Replace the actuator
    Turn power OFF to heating system
    Turn CH and HW OFF at programmer and both HW and CH stats down
    Turn Power ON
    White and Orange wire = 0V
    Grey wire = 240V
    Turn HW ON.
    White and Orange wires = 0v
    Grey wire = 240v.
    Turn HW stat up
    Grey wire = 0v
    Orange wire = 240v
    Boiler should run and HW heat up (Check pipe)
    Turn CH ON and CH stat up.
    The motor should run, then stop.
    Boiler fires (check both pipes from valve are hot)
    White wire = 240v
    Grey wire = 0v.
    Turn HW stat down
    Motor should run then stop.
    White wire and Grey wire = 240v.
    Boiler should fire (It may stop and restart. (Check CH pipe is warm and HW pipe is cooling down)
    Turn HW OFF at timer.
    White and grey wire = 240v
    Motor may run and stop.
    Boiler should fire (It may stop and restart) (CH pipe still hot, HW cold)
    Turn the CH down at stat
    Boiler should go off
    Grey wire = 240v
    White wire = 0v
    The orange wire should have about 100v. It will vary but be well below 240v.
    Turn CH OFF
    Grey wire = 240v
    White wire = 0v
    The orange wire should have about 100v. It will vary but be well below 240v.

    WE can only remove the voltage on the orange wire by removing all power from the valve; this resets the valve.

    PS The blue is neutral so it will always read 0v. Voltages should be measured between the relevant wire and neutral.
     
  16. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page