Leak between cistern and bowl?

Discussion in 'Plumbing and Central Heating' started by Roger465, 15 Sep 2013.

  1. Roger465

    Roger465

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    Well, thanks to you guys, I summoned up the courage to replace my dual flush valve, which has been dribbling into the bowl for a long time. Managed to get everything back together again… all OK till I flushed it, when water poured out all over the floor, from between the cistern and bowl.

    I was careful to make sure the rubber ring between the cistern and bowl was in place, and tightened the wing nuts, but not too tight. So I took the cistern off, all seemed to be OK, so I turned the ring upside down and tried again – water everywhere when I flushed (OK up to that point, so it’s only when it flushes – I assume that means it has to be the big rubber ring).

    What am I doing wrong? Or should the ring be replaced when you separate the cistern and bowl?

    If I do need a new ring, what do I ask for at the plumber’s suppliers?

    I’ll try and include a picture of the toilet…

    Thanks :oops:

     
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  3. denso13

    denso13

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  4. Roger465

    Roger465

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    That's it! With the steel plate and everything.

    So... are you reasonably sure it's just a knackered doughnut?

    Hard to think what else it might be, I suppose...
     
  5. oilboffin

    oilboffin

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    If it's an ideal standard you will need an ideal standard do nut or you won't seal it
     
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  6. Roger465

    Roger465

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    How can I tell?
     
  7. Madrab

    Madrab

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    You also get a foam doughnut these days too but if your one is the one with the backplate etc then Denso's is the one you need.
    If you are getting water ****ing out when you flush then the doughnut isn't sealing. They get ridges etc pressed into them when you fit them that are nigh on impossible to get exactly right when removed and put back together. You do need to make sure that it is well centered when you put the cistern back down otherwise it won't make the seal.
     
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  8. Roger465

    Roger465

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    Yeah the backplate does look very like that – but I’d say my doughnut was more foamy than rubbery, if you see what I mean!

    For me nothing is ever simple…
     
  9. Madrab

    Madrab

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    Usually the foam ones don't have a backplate
    If yours has a plate then it should be a soft rubber with one flat side and a rounded side like the one from screwfix, flat side to the plate.
     
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  11. Roger465

    Roger465

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    I'll let you know!
     
  12. dhutch

    dhutch

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    Otherwise, Silicon the lot!
     
  13. Roger465

    Roger465

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    OK, nothing but bad news so far – have spent several hours now on what I thought would have been a very simple job, and have no toilet. Here’s the story:

    1. When I flush it, water squirts out backwards from somewhere around where the cistern joins the bowl.

    2. I’ve tried re-using the existing seal, both as it came out, and upside down – no difference.

    3. I went to my local plumber’s supplies, with the steel bracket which the two fixing bolts go through, and the seal – they didn’t have that kind, and he didn’t recognise it as one that he’d seen before. All the types he had were different hole sizes, or different seals.

    4. It was either go away with nothing, or try a big foam seal, which was the right size (the original one is made of something half way between foam and rubber). I took the big foam seal.

    5. It sat quite nicely in the recess in the bowl. I lowered the cistern and lifted it a couple of times to make sure I knew how to do it without moving the foam seal, and tightened the wing nuts.

    6. Flushed, and – water came out the back, exactly as before.

    I’m getting close to despair with this. How can it be so difficult to seal an opening which isn't even under pressure? Am I doing something incredibly stupid without realising it?

    What can I do? My dearest wish is that I’d called a plumber, and not tried to do it myself, but plumbers won't come out round here unless you want them to fit an entire new heating system or equivalent.
     
  14. Madrab

    Madrab

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    it should be straightforward and there's nothing worse when it doesn't work.

    1st thing, get a bucket, that will allow you to use to toilet until you get this fixed :)

    How was the plate attached when you took it apart? it should have been held to the bottom of the cistern by the big plastic centre nut of the flush valve, the bolts then hook into the slots on the end?
    If so then as dhutch mentioned, time to silicone the lot.
    1. Take the metal plate off, take the flush valve out and take the rubber seal off the end.
    2. Clean and dry both sides of the washer, the valve and the bottom of the cistern.
    3. Put a bead of silicone on one side of the washer and refit onto the flush valve. Another bead of silicone on the other side of the washer and refit valve into the cistern.
    4. Put some silicone on the flush valve outlet where it sticks through the underside of the cistern and some on the side of the fixing plate that sits against the cistern and reattach it with the flush valve nut, nice and tight.
    5. Put some silicone onto the flat part of the doughnut and use that to stick it, centralised with the flush valve opening, onto the metal plate.
    6. Put some more silicone on the edge of the flush hole where the doughnut contacts the base and then place the cistern onto the base, then tighten the wingnuts to draw the cistern down nice and firmly and make sure it pulls down level.
    Make sure all the surfaces that you will be putting silicone onto are clean and dry. Leave it for 15mins before turning the water on to fill it and then give it a try with your fingers crossed .
     
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  15. Roger465

    Roger465

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    Thanks Rob. Sadly the nightmare continues – I hadn't read your detailed solution when I got back and had another go. I was passing B&Q, and found that they had doughnut kits which looked as if they might fit, and were cheap, so I bought one. My God – it fitted, and seems to be sealing!

    But… somehow it must have moved the cistern slightly, so the water inlet pipe wouldn't quite line up with the plastic threaded bit of the inlet valve. But it was very very close, so I kept trying it, and eventually it seemed to be going on.

    Of course, it was slightly cross threaded, and ruined the plastic threads on the valve, so it leaked. Fortunately, I'd bought a kit of flush AND inlet valves (the inlet valve was supposed to replace a leaking one elsewhere), so there was nothing else for it but to use the new valve.

    http://www.screwfix.com/p/fluidmaster-button-cable-dual-flush-bottom-inlet/58353

    But the nightmare continued. The Fluidmaster instructions told me to raise the height of the inlet valve so that its critical level mark was at least one inch above the overflow pipe. That wasn't possible – at that height, the lid wouldn’t go back on the cistern. So I set it as high as I could.

    It also said it was essential to remove the cap on the very top of the assembly, and turn the water on, to flush any debris out of the valve. Following their instructions very carefully (lift lever, press the cap down, turn clockwise and the cap comes off), I spent about 20 minutes trying to get the cap off – quite impossible.

    Eventually, I lost my temper and prised it off with a screwdriver – this revealed two things: (1) unless I’m completely insane, it is impossible to rotate the cap, due to the way it's fixed in place; (2) when you DO remove it, and turn the water on, the water comes out near the bottom of the valve somewhere – exactly the same as it does with cap on, so I can't see the point in removing it.

    So I filled the cistern – or at least, I tried to, but the water reached the overflow before the inlet valve stopped the water coming in, so it just ran and ran. I can only think that the appallingly bad Fluidmaster instructions were wrong, and that the overflow pipe should be an inch ABOVE the inlet valve, not an inch below??? I took everything apart for the 40th time, and changed it to that – now it fills then cuts off as it should.

    Finally – I filled and flushed several times, and all seemed well… until I noticed a drip coming from the plastic nut which seals the inlet valve to the cistern. I’ve tightened it up even more, and it seems to have stopped… for now?

    Oh – did I say “finally”? Noooo… the dual flush doesn’t. Whether you try to push the little button (impossible unless you have subminiature fingertips), or push the whole big one, you get a short flush – understandable, as there's only one plastic rod that pushes down, whatever you press. So I don't know how that’s supposed to work.

    Oh yes – and the new inlet valve positions itself exactly in front of one of the holes in the back of the cistern where the screw is supposed to go through to the wall. I hadn't put the screw in yet, as up to now the tank had needed a fair bit of wiggling while trying to line things up.

    I think words like “nightmare” are overused, but I’ve spent something like 4 stressful hours on this, made a hell of a mess, it still doesn't work properly, and I have no confidence it won't suddenly spring a leak in the middle of the night and flood the house.

    I’m a computer engineer – although I don’t know a lot about plumbing (as is clear) I do know how to work carefully and logically, and I can happily fix cars and domestic appliances, re-wire things, do minor building, carpentry etc. But this has defeated me completely.

    Nothing fits; instructions are wrong; valves and things don’t work in the way they should etc etc etc.

    Never again. Maybe these things are best left to the professionals.

    But thanks again for all your help :unsure:
     
  16. Madrab

    Madrab

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    Sorry to hear you had a mare of a time Roger. It's one of those things where it either all goes together without a hitch or all hell breaks loose and everything goes wrong.
    I suppose it's a testament to all the years of training and experience which allows us to get things fixed when things go wrong but let me tell you not always, we all have bad days.... :D
     
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  17. Roger465

    Roger465

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    Cheers Rob – it’s still leaking from the joint between the inlet valve and the cistern. I daren’t tighten the plastic nut any more! Might be leaking from the inlet pipe/valve junction too. Those pipes might I think be under some tension as the cistern seems to have moved very slightly to the left after fitting the new doughnut…
     
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