Central Heating Problem *** FIXED ***

Discussion in 'Plumbers' Talk' started by iamwoody10, Mar 29, 2014.

  1. iamwoody10

    iamwoody10 New Member

    Hey Guys .... and Gals :oops:

    My heating only works when my hot water is on ??

    I have a potterton Suprima 50L, It has a water tank in the loft, 2x 2-way zone valves and 14 Rads.

    The hot water works perfectly on all cycles.

    The heating - when I turn the thermostat, the zone valve light comes on and the synchron motor works, i took the motorhead off and the pipe valve is open but the boiler does not fire !!

    I dont really know what else to check

    any help would be gratefully appreciated

    Andy
     
  2. I'm guessing the zone valve has a micro-switch in it that activates when it's fully open and this is what turns on the boiler. So, if that switch is faulty, your boiler won't turn on when just on CH mode.

    So that's where I'd look - do you know how to check your wiring centre?

    The actual switch is inside the motorhead - chug chug chuggie chug...
     
  3. iamwoody10

    iamwoody10 New Member

    Thanks for the swift reply.....

    i dont know how to check the wiring, but i could swap the heating and water ones over to see if the problem swaps !!

    that would tell me ??
     
  4. The two motor heads? I guess so :)

    Are they easy to disconnect? Do their cables go to nearby junction boxes?

    But, really, it should be simpler than that.

    Do you have a test meter? No? Well buy one - sheeesh.

    Do you have a neon test screwdriver? Yeah? Cool - but do bear in mind they are carp and should never be relied on...

    Ok, follow the cable from the motor head (are they called 'actuators' or summat?)

    Anyways, open zee junction box and look inside... You should have:

    BLUE - This is the Neutral. It should be neutral all the time.
    BROWN - this is the Live, but it only becomes 'live' when the timer and room stat calls for heat.
    GREY - this is the live to the micro-switch and will likely be live all the time - so don't stick your tongue on it.
    ORANGE - this is the output from the micro-switch - this should become 'live' when the valve is fully open (and I suspect doesn't...)
    Oh yeah - and the GREEN & YELLOW wot is earth and quite important.

    If you have a test meter, then switch to AC volts and greater than 240. Place one probe on the neutral (blue) and t'other on the Grey - this should show 240V to prove it's getting power and you are still alive.

    Now transfer the 'grey' probe to the Brown - and ask someone to twiddle the room stat up and down - with the central heating timer also on. This should show 240V when you turn the stat up (and the motor should activate - don't wet your pants when you hear the buzz...) and 0V when stat is turned down - and the valve should close again with its return spring.

    Ok, getting warm. Now put that same probe on to the Orange and get the room stat turned up again. The motor goes buzz, you go 'eek' and you should get 240V showing a couple of seconds later when the valve is fully open.

    If there is 240V, then everything at the valve seems to be in order, so you need to trace why that switched live isn't getting to and turning on the boiler.

    If, however, it remains at 0V, try hitting the motor head gently with a screwdriver handle or summat to see if you can 'shock' the micro-switch into operation.

    If you only have a test screwdriver, then do all the above with no need to have a probe on the neutral.

    OBVIOUSLY DON'T KILL YOURSELF 'COS THAT WOULD BE POINTLESS and we won't know if you've fixed it or not.
     
  5. plumberboy

    plumberboy Well-Known Member

    I hope he comes back.:oops::eek:
     
  6. iamwoody10

    iamwoody10 New Member

    Hey Guys....
    Just to let everyone know....
    Thats it fixed !! Woohoo.... it was indeed the Motorised Valve that was faulty.

    I didnt realise it had a microswitch in it, I thought it only had a motor to open the valve.

    So its true..... Everyday is a school day :p

    Many Thanks again..

    You saved me a trip to the hospital..... the earache would have been terrible ... hahahaha
     
  7. :D

    And a real bonus that you are still alive... :rolleyes:
     
  8. tom.plum

    tom.plum Screwfix Select

    aw shucks, everybodies fixin' their own problems now, the governments givin' out boilers left right and centre, how's a plumber suppose to live?
    think i'll go into the pop world :)
     
  9. You need to buy yourself a geetar for that career change :rolleyes:.

    (You do realise, don't you, that it's potential customers reading about your profligacy (always wanted to use that word) that makes them want to DIY?)
     
  10. Sean_ork

    Sean_ork Screwfix Select

    the government isn't given out boilers left right and centre either :rolleyes:
     
  11. tom.plum

    tom.plum Screwfix Select

    ( not a problem (getting a geeter) I meant,(plus i did't think it was legal) to use brackets inside brackets)
    :eek:
     

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