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Toilet fill valve replacement

Discussion in 'Plumbing and Central Heating' started by Larches, 17 Sep 2020.

  1. Larches

    Larches

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    I need to replace a bottom-entry fill valve but there are a few things I'm not sure about.

    Firstly... the existing (original) valve is a Roca one, and I'm having trouble identifying exactly which part it is because there seem to be at least a couple of different variants out there that look very similar. However, is there any need to replace it with a Roca one or am I better going for a generic brand such as Fluidmaster or Torbeck (ideally with a brass shank rather than the plastic one on the Roca)? I'm guessing that should be fine as long as I check measurements and adjust it as required.

    Secondly, there seem to be at least a couple of different shank sizes available, the most common being described as 1/2". I hope this isn't a daft question, but what is this actually a measurement of? The inner diameter of the shank, or the outer diameter (including thread), or something else? Reason for asking is that the existing one doesn't seem to measure 1/2" anywhere obvious. The inner diameter is 1.5cm (= some obscure number in inches, perhaps because it's from a European manufacturer?). I've seen 3/8" European models mentioned online but that would be just under a centimetre which seems very small and also doesn't seem to correspond to the existing part, unless I'm measuring the wrong thing.

    Finally, I noticed when removing the existing valve that it had been sealed into place using something that I presume to be normal sanitary silicone - it was between the rubber gasket where it meets the inlet in the base of the cistern, and all the way through that inlet hole filling in the space between the shank and the ceramic (which would otherwise have had maybe a 1-2mm gap around the circumference of the shank, although maybe that's not a problem as long as the gasket does its job properly). However, I've never seen instructions advising the use of silicone when fitting a fill valve, so I'm not sure if it's necessary or even advisable, or whether it's down to a size mismatch or just someone taking the initiative. I had thought about using a bit of plumber's putty around the thread when reconnecting it to the inlet, but apart from that I hadn't anticipated needing to use sealant.

    Thoughts or advice on any of these points would be welcome - thanks in advance.
     
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  3. Chris_W

    Chris_W

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    I suggest cleaning off any old silicone/sealing compound. The 1/2” usually refers to British standard pipethread, and not the diameter measurement. No need to get a Roca one, just a generic one will do, but do go for a branded one such as fluidmaster, torbeck, Thomas Dudley, Siamp etc. Chances are it’s 1/2”, but obviously without being in front of it or a photo then unable to say otherwise.
     
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  4. just pumps

    just pumps

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    1/2" shank = 20.99mm outside thread
    3/8" shank = 16.66mm outside thread

    As said remove ALL the old silicone ready for a smear of new. The new valve should come with a cone washer to fit underneath which centralises the shank in the hole of the cistern. With a brass shank you will need a new fibre or rubber sealing washer but nothing else to seal the threaded joint.
     
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  5. Larches

    Larches

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    Thanks both, and yes mine does appear to be the 1/2" based on that thread size. Just having a look at options now - the Fluidmaster ones look good although the warranty info is confusing (their own site shows one with a 1 year guarantee, one with 7 years, and then retailer site says 5 years o_O). Or there's the Torbeck Ecofil (only 1 yr guarantee but supposedly water-saving... not sure how that works!). Both seem a reasonable price and fairly compact so hopefully no problems fitting my compact cistern.
     
  6. just pumps

    just pumps

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    Personaly, I don`t like the Torbecks any more but each to their own.
     
  7. Chris_W

    Chris_W

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    Torbeck (opella) are under the same umbrella as Fluidmaster anyway. Personally I wouldn’t be that bothered about a warranty for a fill valve, I don’t think they’d send anyone out (I could be wrong).
     
  8. Larches

    Larches

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    Yes I noticed the Torbecks show up on the Fluidmaster website and guessed there might've been a takeover or merger. I can't imagine they'd send anyone out either, but thought at least if it stopped working properly (as some reviews suggest) say a year down the line then it would be good to be able to ask for a replacement rather than forking out for a new one on a regular basis. To be fair though, the majority of reviews seem pretty positive.
     
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