Heating pump won't stop.??

Discussion in 'Plumbers' Talk' started by jimmyybob, Feb 12, 2017.

  1. jimmyybob

    jimmyybob New Member

    Hi, I have recently moved house and I can't get my head around the heating system.
    The pump runs day and night without ever stopping.?
    The heating and hot water seems works as and when it should but even when the timer is off the pump still goes.
    There is a small glow worm micron in the garage,two black tanks in the loft an immersion tank in the cupboard with two zone valves and a pump.
    The only way to stop it is to pull the fuse.
     

    Attached Files:

  2. Hmm, a possible answer as to why it's running 24 hrs is obvious - the way the pump cable feeds in to the FCU rather than in to the white 'wiring centre' box to the FCU's right. But - if this were the case - it would beg the question 'why' wire it this way?

    Of course, it could chust be passing right through the FCU on the way to the WC beyond.

    I wonder if having the boiler installed a distance away means there's residual hot water left in the flow pipe when it runs off and causes noises, so this is the plumber's 'solution' to sorting it? Jeepers...

    Jimmy, how confident are you around leccy? It would help us if you could removed the cover on that wiring centre and close-up photograph the inside, and also remove the FCU and pull it away gently and ditto a close-up.

    You should turn off the power at the main CU before doing this.
     
  3. leesparkykent

    leesparkykent Well-Known Member

    If the boilers not firing up but the pump is constantly running then it sounds like the pump is wired to a permanent live rather than the appropriate switch live. IIRC this boiler doesn't have over run so the brown of the pump should be connected to the same terminal as the oranges from the valves.
     
    Deleted member 33931 likes this.
  4. jimmyybob

    jimmyybob New Member

    IMG_2478.JPG IMG_2477.JPG IMG_2476.JPG i hope this helps.
     
  5. jimmyybob

    jimmyybob New Member

    The property (bungalow) was built in 99/2000
     
  6. Good lawd!

    There's summat funny going orn, as far as my limited eyes can tell.

    The boiler in the garage, does this also have a FCU (Fused Connection Unit with switch) beside it? Any chance of a photo, showing whatever controls and cables are feeding it?

    Ok, the only things I can surmise from these photos are that the FCU is not 'powering' that wiring centre as it should be. I was expecting a live supply (from your main CU 'fuse box') to be coming in to that FCU and then the switched side of it then supplying that wiring centre. Instead, there is only ONE T&E cable I can see in there between them, and that looks as tho' it's going to the WC to get power and the other side of the FCU is then supplying the pump! Therefore I can only guess that the FCU is getting its power from the WC and is then supplying the pump - if so, crazy.

    You can test this by turning off that FCU - does the pump stop? And does the boiler keep on running (if it was on before)? (If so, turn the pump back on - the boiler shouldn't run without the pump doing so too!)

    Back to the WC. There's a white cables entering it from below - is there chust one? I presume this is going to the cylinder 'stat? Do you have a room 'stat as well? If so, where does its cable go to?

    Can you clarify how many cables are actually entering that WC in total, and where they are coming/going from?

    (And, what are your sparky skills like?)
     
  7. leesparkykent

    leesparkykent Well-Known Member

    Looks like the red (live) from the grey cable in the fused spur is connected to the terminal in the wiring centre that the greys of the valves are connected to which is permanent live, then the pump is fed from the the load side of the fused spur. This isn't a convential way to wire such a system and would beg he question as to why the pump is permantly fed....The pump would normally be connected to the same terminal in the wiring centre as the oranges which only becomes live when one or both of the valves opens which then would normally run the pump and fire the boiler.
     
  8. jimmyybob

    jimmyybob New Member

    IMG_2484.JPG Turning off the fused switch stops the pump.

    fused switch to the pump is connected.....second from left is the black(with blues). fourth is the red(with grays).

    The white cable that comes up goes to the stat on the immersion.

    Turning off the isolation switch in the garage also stops the pump.
     
  9. But the boiler doesn't?
     
  10. Better photo - it shows three further cables coming through from enderneath.

    I'm guessing these are Room Stat, Power supply from the FCU in the garage, and - er - possibly the return supply to turn the boiler on and orf?

    But I'd have to spend a bit more time looking at it.

    So I'm hoping Lee will do this instead... :oops:
     
  11. jimmyybob

    jimmyybob New Member

    Yes the isolation switch next to the boiler also turns it off.
     
  12. Oh gawd - three posts to get one answer... :rolleyes:

    Can you confirm - turning orf the FCU beside the WC turns off ONLY the pump and NOT the boiler? And turning orf the FCU beside the boiler turns orf EVERYTHING?

    Ta muchly... :)
     
  13. As Lee - the sparky - said before, the pump should almost certainly be connected to the Orange wires coming from the two 2-port valves - the third terminal from the left in this photo.

    That terminal currently has three wires in it - the two Ornages (from the valves) and one Red. That red is very likely (ie, it should be...) the live signal to the boiler to come on. But obviously we cannot tell from here if that's where it's going. But almost certainly it is. But we can't guarantee it. But it should be. But who knows?

    So, in THEORY, if you were to take the RED that currently goes to the pump (via its nutty FCU) from terminal 4 and instead place it in term three, then in THEORY that's the way it should have be done.

    BUT, whoever wired this added that FCU for some reason that we cannot possibly know, so if you wanna try this change, on YOUR head be it. :)

    g.png
     
    leesparkykent likes this.
  14. jimmyybob

    jimmyybob New Member

    So....
    The isolation switch in the garage turns off the boiler AND the pump.

    The switch in the immersion cupboard only turns off only the pump NOT the boiler.
     
    Deleted member 33931 likes this.
  15. KIAB

    KIAB Super Member

    I reckon it would be better to get a spark in & rewire the lot correctly, as at present it's a right mess.
     
  16. leesparkykent

    leesparkykent Well-Known Member

    If you disconnect the red that's with the greys and connect it to the terminal with the oranges then
    I concur :)....I sort of give up on the thread as the op didn't seem reply directly to questions or advice o_O
     
    Deleted member 33931 likes this.
  17. kiaora

    kiaora Guest

    Hi
    Looks like the pump live is connected to the grey, , that's the wronge connection

    Connect the pump live to the orange wires, switched live....

    Regards
    Peter
     
    Deleted member 33931 likes this.
  18. Thanks for the confirmation, Lee and Kia.

    Jimmy, there should be little risk in trying this at least - it'll either work (it should work) or it won't. Turn off the FCU near the boiler - but ALSO switch of the MCB in the CU that supplies this circuit. Leave the FCU beside the WC on.

    If this doesn't work, it'll almost certainly be because whoever wired it the existing way did so for some bizarre reason I cannot fathom. But perhaps that reason might become clear when you make the change... :eek:
     
  19. It's mostly not a mess, chust pretty normal for a WC.
     
  20. jimmyybob

    jimmyybob New Member

    Woooooh,
    I really appreciate your time and effort in replying to my rambling, Ive literally spent every hour of the weekend moving house and diy/curtains and that jazz.
    I'm sorry I haven't had time to act on your advice and I've replied to all that I can when I've had a spare second.

    So in conclusion I will switch the two wires over and report back as soon as I can.

    Thank you for all your help thus far.
     

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