How does toilet overflow work on new siphons?

Discussion in 'Plumbers' Talk' started by Johnny_D, Apr 1, 2010.

  1. Johnny_D

    Johnny_D New Member

    I want to replace the siphon on my toilet. It has an 'Overfloat' device which acts as an overflow - but it is fiddly piece of kit.

    I have bought Toilet Siphon 203mm (8")No: 44047 from ScrewFix which says it has an internal overflow. I can't see how the overflow would work though.

    Any help really appreciated,
    JD.
     
  2. sinewave

    sinewave Screwfix Select

    The overflow mechanism is inside the syphon and to Joe Public is 'invisible'


    If the water in the cistern gets too high it will just start to dribble from where the main flush comes from.


    However if ya pans blocked also then yer up * street! :^O

    [Edited by: admin]
     
  3. Crowsfoot

    Crowsfoot Screwfix Select

    Any help really appreciated,
    JD.

    I have an FTC in building science you know!
    Here goes,
    It works on atmospheric pressure exactly the same way as the auto syphon at the gents urinals works.
    It should sit quite low in your cistern which enables the air pressure pushing down on the water in the cistern to overcome the pressure of the air which got trapped at the top of the syphon which then results in the water starting to trickle into the WC pan.
    Albert Einstein,
    (it's Tappy really :)),
     
  4. Dubs

    Dubs New Member

    ZZZZZZZZZZZz overflow is built into the syphon water therefore ends up in the pan. All work differently so its pointless trying to give a scientific explantation.

    For example on a roca it simple just pours into a tube.....simple as that.
     
  5. tomplum

    tomplum Active Member

    as its the first of april, tappies explaination gets 10/10 whereas dull dubs gets a mere 1/10,
    now the facts,
    in the year 2000 the water bylaws changed to European standard, overflows where to never again to be used because the fat euro democrats say so .
     
  6. Dubs

    Dubs New Member

    They don't all work on atmospheric pressure, Dudley Turbo do but most centre push systems are simply just a tube and a punched washer to allow water to flow bypass the syphon details.....gravity.

    I once was asked at a plumbers merchant what can go wrong with a float valve by a DIY customer....I told him not to worry about what can go wrong with them and just replace the the whole unit rather than messing around with washers and flow restrictors.

    Same applies to syphons...why worry how they work. It's not important. What is important is that it does work. If it doesn't work then replace the faulty item.
     
  7. Crowsfoot

    Crowsfoot Screwfix Select

  8. palavaman

    palavaman Well-Known Member

    as tom rightly pointed out, under current regulations, all syphons should incorporate an internal overflow.

    OP not contented with replies :) well, he/she should ring the manufacturers of the one they have bought and they'll tell him/her all about the technicalities of how it works???

    then again, as one poster already stated, why bother how they work? they do work, period!!!!!
     
  9. ThreadJacker

    ThreadJacker Active Member

    You need to know how they work to adjust the water level correctly, the height of a syphon refers to the spillover level at the top of the syphon. The water level in the flush handle part of the syphon is always the same as the water level in the cistern so when the cistern overflows the water spills over and down the tube into the pan.

    To get a toilet than flushes on the first pull of the lever requires the water level to be just right, too high and it will constantly overflow but to low and the syphon action will be harder to start.

    Simpy poo poo's
     
  10. Captain Leaky

    Captain Leaky New Member

    Some cisterns leak our out the handle hole before the water rises to the internal overflow ;) interesting :)
     
  11. imran_

    imran_ New Member

    It just ain't so difficult. When the water level reaches the bottom of the blue bit it will automatically drip into the bowl or cause a siphonic effect. As others have said the syphon needs to be sized so that it doesn't **** out the handle.

    Alternatively get a flapper where the internal overflow can be cut down as required.
     
  12. TM

    TM New Member

    hi there i also have two toliets with the Overfloat device ,did you find anywhere still stocking this product ?

    TTM
     
  13. G Brown

    G Brown New Member

    Fit a Fluidmaster dump valve kit.
     
  14. Stuart Jnr

    Stuart Jnr New Member

    JD.

    All siphons have an internal overflow built into them, and will work as an overflow as long as the hole for the lever is not lower than the siphon your replacing i.e the original was a 7.5 inch siphon and your replacing it with an 8inch.
    Basically the cistern will continue to fill up and travel through the bellow, up to the top of the siphon down the other tube and into the pan. Nothing ingenious to any manufacturer!

    My advice is to buy a 2 piece or 3 piece siphon. Stay well away from 1 piece siphons
     
  15. Stuart Jnr

    Stuart Jnr New Member

    Fit a Fluidmaster dump valve kit.

    Why?
     
  16. Captain Leaky

    Captain Leaky New Member

    Why?

    They are the best thats why!
     
  17. Stuart Jnr

    Stuart Jnr New Member

    They are the best thats why!

    Says who?
    Definitely not the bathroom manufacturing industry!
    They are sold purely on price an they only have a 12 months guarantee!
     
  18. G Brown

    G Brown New Member

    We plumbers know they are the best . Why? Because we have to replace the rubbish fitted as OEM by the manufacturers!
     
  19. Stuart Jnr

    Stuart Jnr New Member

    I'm sorry but there are many other valves out there that are far superior to the Fluidmaster cable operated valve.
    Plumbers prefer the fluidmaster because its cable operated and there's no fuss!
    IMO the fact that it only has a 12 months guarantee, a standard guarantee for rubber components within the bathrooms industry.Just goes to show the faith the manufacturer has in its own products.
    If the valve was considered to be the best then why is it, Geberit, is used by ALL the top manufacturers of Sanitaryware for their more expensive toilets?

    I completely understand why plumbers prefer the Pro45 inlet valve, or why the FM cable valve has done so well with tradesmen like yourself, but there are better options out there!

    Also, from a manufacturing point, everytime a plumber takes the cistern internals out of a prefitted cistern, you could actually be causing faults! Every pan and cistern sold with prefitted cistern fittings has been tested to work at maximum effeicieny!
     
  20. G Brown

    G Brown New Member

    WHAT!

    Do you believe the drivel you write?

    I have lost count of the amount of pre-assembled cisterns that are faulty!

    pfffft! keep digging! :^O
     

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