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Discuss Urinal flush valve help? in the Plumbing Forum area at UKPlumbersForums.co.uk.

  1. macka09

    macka09 Plumber GSR

    hi guys. Currently stood in front of a wall hung urinal that slightly over fills on flush. It has a p trap rather than a bottle would this make any difference to flow rate? I can’t seem to adjust the flush valve. It’s not a cistermiser it’s just a constant fill and then at a level the flush kicks in. I thought the flush valve on these were screw up and down but it doesn’t budge. Any tips?
  2. Ben-gee

    Ben-gee Plumber

    Trap partly blocked? (Or pipework)
    Either “pi55 cake” gunge or foreign object?
    • Agree Agree x 1
  3. Stigster

    Stigster Plumber

    The trap and/or waste pipe could be partially blocked. I have to deal with this situation occasionally and it's not a nice job as the traps are often about 50% full with crud from urine and the stuff is foul. As foul as can be in fact. This obviously causes a restriction on the waste pipe and the bowl trying to empty. It wants cleaning out most likely or if you can't face that replace with a new one. Whilst the trap is out try to see inside the waste pipe too. Last one I did was almost 50% full with a hard scale. I ended up cutting that out and replacing back to the stack as it was a very short run.

    As for it being a P trap, in my experiments they have shown to have less resistance and better flow rates than a bottle trap so I don't think the type of trap is the problem.
  4. Ben-gee

    Ben-gee Plumber

    I’ve seen pipes blocked too I think it’s Uric acid crystals from pee, much more soluble in hot water if you want to try to clear - but as stig says more pleasant to cut out and replace.
    Get a clothes peg for nose...
    • Winner Winner x 1
  5. Last Plumber

    Last Plumber Trusted Plumber GSR

    You're going to have to get stuck in. It's a tad unpleasant but C'est la vie.
    I worry more about the individuals who's urine that solid matter comes from to be honest. I know we all have it but in some circumstances I have been convinced it is down to the powder type coffee / drinks machine.
  6. macka09

    macka09 Plumber GSR

    No the trap is spotless chaps and the 1 1/2” waste pipe that goes down through the floor seems fairly clear also. A colleague has already been out put chemicals down. I can’t seem to adjust the volume of water on the flush but I’m assuming the flush volume has been the same since day one. This is why I queried whether it could be the trap restricting the flow of water. It literally comes out of the trap and down through the floor so not many fittings to contend with. It’s a 3rd floor office toilet.
  7. Last Plumber

    Last Plumber Trusted Plumber GSR

    What size is the sparge pipe, has it got a spreader on the end of it?
  8. bogrodder

    bogrodder Plumber GSR

    I repiped a set of urinals in a big steel handling plant, years of [email protected] gunge blocked everything. Worse one I’ve ever done, did everything to protect myself.. actually looked like an extra from the mini series ‘Chernobyl’ , but I still went home stinking of the toxic organic gunge

  9. bogrodder

    bogrodder Plumber GSR

    Probably the worse job, us plumbers do.
    • Agree Agree x 1
  10. bogrodder

    bogrodder Plumber GSR

    Oddly I find rodding drains therapeutic..
  11. macka09

    macka09 Plumber GSR

    Drains are clear chaps. I’ve fitted an anti syphon trap and it’s worse. The flush syphon is non adjustable so I have no idea
  12. macka09

    macka09 Plumber GSR

    Anyone seen this before

  13. Harvest Fields

    Harvest Fields S. Mod Trusted Plumber GSR Top Contributor!!

    Nope and I wouldn’t be touching it without gloves on.
  14. Ben-gee

    Ben-gee Plumber

    It looks a bit like ‘my friend’s’ “anal intruder” not sure if your one is xl or xxl?
  15. snowhead

    snowhead Plumber

    That's an autoflush syphon, non adjustable.

    I'd say it's a waste pipe (partial) blockage.
    Chemicals won't shift the blockage.

    I've cleared and or repiped hundreds, many of them the same urinals over the last 25 years of my working life, in supermarkets.

    Get a bucket of water and use it to fill the urinal.
    Pour it in at a fairly steady rate and it should keep up with the flow.
    If it's partailly blocked, it'll back up reasonably quickly.

    If it runs clear then disconnect the trap and let the urinal drain into a bucket (have spare empty one standing by) using the autoflush
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