1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

3 Port Valve - Replace the whole thing or just the head? Videos included!

Discussion in 'Plumbing and Central Heating' started by DIYNotIan, 7 Sep 2021.

  1. DIYNotIan

    DIYNotIan

    Joined:
    8 Sep 2010
    Messages:
    805
    Thanks Received:
    14
    Location:
    South West Wales
    Country:
    United Kingdom
    Hi plumbers and DIYers

    I made a post about my 3-port valve a couple of weeks ago, but have finally been able to take a look and thought best to start a new one than tag on. Hope that's ok.

    Recap: We've had a problem whereby our boiler will only heat the radiators, even when set to hot water only. Pretty certain the problem is with the three port valve.

    With the electricity off, I've removed the head and taken a video to show what happens internally when I move the lever. As you'll see, it slips and clunks. Does that mean that the gears are knackered or is it something else completely? Is it fixable or time for a replacement? Or is it normal? Must say the vids I saw had smooth looking mechanisms...

    If it is time to replace the head, should I just do that or do the whole unit? The spindle moves quite freely by hand, as per the third video. It only moves from say 12 to 1 one o clock, but I think that's the normal range isn't it? Is there any other way of telling what condition the T pipe piece is in?

    Money is really tight, and if just the head needs replacing I'd be confident doing that myself plus the part would be a bit cheaper.

    But in a few weeks we are having plumbing work done in the house which will involve a drain down. So if it is a much better idea to change the whole thing then that would be the time to do it, and I'd bite the bullet on the extra £££.

    Hopefully the videos can help shed some light:

    https://drive.google.com/drive/folders/1uDVtF8t8_L7f5pekzgGtGM89wzy4q7nN?usp=sharing

    Much appreciate any replies :)

    Cheers

    PS - Hollywood here I come!
     
  2. Sponsored Links
  3. kidgreen61

    kidgreen61

    Joined:
    8 Mar 2009
    Messages:
    2,345
    Thanks Received:
    538
    Location:
    Staffordshire
    Country:
    United Kingdom
    First of all try the spindle on the valve to see if it moves easily (only a few degrees either way) with your fingers.
    If it does, just replace head, if it is seized, replace the whole thing
     
    • Thanks Thanks x 2
  4. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    22,853
    Thanks Received:
    9,261
    Location:
    Lanarkshire
    Country:
    United Kingdom
    valve looks fine so just change the actuator head, the gearing mechanism is slipping, buy a genuine honeywell one and not the cheap imitation ones
     
    • Thanks Thanks x 1
  5. DP

    DP

    Joined:
    10 Dec 2003
    Messages:
    14,635
    Thanks Received:
    3,202
    Location:
    Glasgow
    Country:
    United Kingdom
    Honeywell actuator will do that when not attached to the valve. I would put the actuator back onto the valve and then attempt what you are doing
     
    • Thanks Thanks x 1
  6. DIYNotIan

    DIYNotIan

    Joined:
    8 Sep 2010
    Messages:
    805
    Thanks Received:
    14
    Location:
    South West Wales
    Country:
    United Kingdom
    Many thanks the replies

    Interestingly, I have asked about this on other forums too. And I've also had a plumber visit since originally posting. There's a real mixture of replies, with some saying just the head needs changing (which includes the plumber), and others adamant that the head is fine and just the valve needs replacing.

    I guess that's the internet for ya!

    Fair play, I'll give that a go. Once reconnected, when I try again is it ok to do so with the power off or does it need to be on?

    Cheers
     
  7. DP

    DP

    Joined:
    10 Dec 2003
    Messages:
    14,635
    Thanks Received:
    3,202
    Location:
    Glasgow
    Country:
    United Kingdom

    With power off actuator attached to the valve. With cover still off try different permutations and see what the valve is doing. When valve mid position look at the lever that is close to the micro switches.
    With just heating on, micro switches operate.
    With just hot water calling the valve restores under spring action.

    if it does not, either the valve spindle is causing this to happen else spurious induced voltages. Put power off, if valve now restores to home position, then it is spurious voltages.
     
  8. Sponsored Links
Loading...

Share This Page