Flap valve improvment?

Discussion in 'Plumbers' Talk' started by teabreak, Aug 27, 2019.

  1. teabreak

    teabreak Screwfix Select

    Hi, I have the most useless concealed cistern in the downstairs toilet, the low flush barely dilutes the colour of wee and the full flush often needs two goes for anything solid!
    It is a Fluidmaster and a call to them having done all the usual checks resulted in tacit agreement because the staff member had the same unit.:D
    The pan is a modern one fitted at the same time.
    I asked if there was a way to convert the button to single flush to save the need to tell guests to go for a full flush the first time, ;) but it seems not.:(
    I wonder if fitting a flap valve with a push button is likely to give any significant improvement.
    Any ideas please?:)
  2. furious_customer

    furious_customer Screwfix Select

    Less fiber in your diet :)
  3. DIY0001

    DIY0001 Active Member

    Check the water level in the cistern fills up to the maximum line. That should get you the biggest full flush. If it isn't then adjust the float on the inlet valve to get more water in the cistern. There might also be an adjustment for the low flush level on the flush valve/syphon: either clips that pull out or slide up/down.
  4. teabreak

    teabreak Screwfix Select

    Thank you for your help, but I did all that before speaking to the maker.:(
    The level is as high as I can safely set it and it does empty but it is still **** I have had one of these pans before on a low flush cistern and while not Niagra Falls it did work better.
    I am thinking the only solution may be to try and source a replacement cistern for the older flush volume and try to shoehorn it into the space!
  5. Joe the Plumber

    Joe the Plumber Screwfix Select

    It might be worth checking the chamber in the back of the pan where the flush pipe goes into it. I've had the very occasional one where debris has got into it and was restricting the flow of water into the bowl.

    Sometimes it was possible to see the debris sticking out under the rim at the back of the bowl using a mirror and a torch.

    Sorry if you've already done all this.
  6. teabreak

    teabreak Screwfix Select

    Just an update if it is of help or interest to anyone.
    I stripped it out and did find a restriction from a misplaced seal, but as I had the flap unit I decided to go ahead and fit it anyway.

    It went in fine although the button supplied operated when you raised the seat and lent it back! :( An auto flush device!:p
    I did a bit of cobbling together and got the original (flusher fitting) button to work with it.

    The old flush pipe had a sharp bend almost an elbow, the new one I fitted is more of a swept bend, which I suspect helps too.

    The results are good. Certainly there was a restriction causing trouble, so that helps a lot, however the old flush unit seemed to open slowly so the first water was a trickle that built up, while the new one is instant full flush, also the low flush only let a drop of water out barely dropping the level while the new low gives a good flush of about a half of the cistern.

    New.JPG Old.JPG seal.JPG
    Last edited: Sep 30, 2019
  7. Mrs Plumber

    Mrs Plumber Member

    I love these flapper valves, simple and effective. I've fitted them to commercial Saniflos that kept getting bunged up, not had trouble since. Brilliant things.
    teabreak likes this.

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