Intermittent Flush on close coupled WC

Discussion in 'Plumbers' Talk' started by Glenne Nelson, Aug 17, 2019.

  1. Glenne Nelson

    Glenne Nelson New Member

    Toilet flushing intermittently. Sometimes it flushes first time, sometimes after several attempts. If it doesn't flush at all after 5-10 minutes it flushes first time. Everything visible in the cistern is fine including water levels. having a read about points to the diaphragm or something in that area. Are we looking at a siphon assembly replacement or a repair. Call a plumber? I have and he hasn't responded. I'm good at DIY, I have the tools and skills, I am retired and have plenty of time on my hands so why not have a go myself.

    Thanks for any advice,

    Glenne
     
  2. terrymac

    terrymac Screwfix Select

    Just replace the diaphragm. Some siphons allow disassembly ,but others entail having to remove the siphon from the cistern, which has to be removed from the pan. Can you post pics ? You may also have a low water level in the cistern.
     
  3. Heat

    Heat Screwfix Select

    Some siphons are made of 2 demountable parts and can easily have the part with the siphon washer removed simply by reaching into top of cistern.
    If it is the more common one piece siphon it will require the siphon to be removed from base of cistern, which if it is a close coupled toilet means the whole cistern has to be removed.
    You might need a suitable siphon washer unless you fancy cutting an accurate sized and shaped new washer from a heavy piece of polythene sheet. Or new siphon.
    Also might need new donut washer, new washer for water supply connection (if that type of connection).
    I often replace the fill valve/ball valve with a brass tailed valve as many are old and work poorly and at risk of cracking at threads.
    So many possible parts, that it could be surprisingly difficult.
    I take a van load of parts, so you might find you won’t have the correct parts.
     
  4. Glenne Nelson

    Glenne Nelson New Member

    Will get some pics tomorrow. It's not the water level as I adjusted the cistern to fill up and it made no difference (unless you can overfill). It looks as it's a remove cistern from wall and siphon job. I'm quite happy to replace the whole assembly. thanks for your response.
     
  5. Glenne Nelson

    Glenne Nelson New Member

    I will take my chances with a complete piston assembly (I assume most are a UK standard size and fitting). I may also have a look around and see if anything else may need upgrading. Thanks for your response.
     
  6. Heat

    Heat Screwfix Select

    Err, ....- don’t get a piston assembly or it won’t work, whatever that is? :p

    The siphons can come in different heights. Or you could buy the adjustable type.
    Dudley is one brand, but cost more.
    Fixing the old siphons is usually just a washer replacement without any other issues
     
  7. Glenne Nelson

    Glenne Nelson New Member

    IMG_8762.JPG IMG_8763.JPG
     
  8. Glenne Nelson

    Glenne Nelson New Member

    Erm, meant Siphon not Piston. Can't even blame predictive text.
     
    Heat likes this.
  9. Heat

    Heat Screwfix Select

    A few things I notice, - the screws holding cistern to wall look like steel rusted, and some can be difficult to remove. Brass or stainless steel better and use a rubber tap washer as a soft washer.
    The all plastic ball valve is likely to be a noisy type and not great on mains pressure.
    The flush handle might be corroded and the plastic link could be seized on. Obviously the self tapper screw is badly rusted.
    The siphon is unusual brand I think and you probably should consider replacing it. Our host has various types starting from about £5.
    If you have another loo in your house you could dismantle that cistern and find out what has to be replaced.
     
  10. Glenne Nelson

    Glenne Nelson New Member

    Yes I had a look at the screws yesterday and was a bit worried that they were rusted. Sprayed with WD 40 and fortunately today they unscrew fairly easily. We only have the one loo which is why I considered a plumber (in case there were any unseen difficulties) instead of a DIY attempt.
     
  11. xednim

    xednim Screwfix Select

    not to difficult to replace, if you are doing for first time should take you approx. 2h, those siphons are cheap and better to replace entire unit than try to find diaphragm
    advise- as spongy seal between the seat and cistern will be worn prepare a silicone and smear around it on installation to make sure if it won't leak, unless you will buy replacement prior your repair
     
  12. Glenne Nelson

    Glenne Nelson New Member

    Good idea the silicone. My idea was just to purchase a new siphon and have it ready while I remove the existing as you suggest. Will this come with all washes/seals needed or will they have to be purchased separately.
     
  13. xednim

    xednim Screwfix Select

  14. The Teach

    The Teach Screwfix Select

    does it flush any better with the saver bag removed ?

    if your going to exchange the complete siphon,Have a wd40 spray on the wing nuts under the pan that hold the cistern in place before dismantling.

    A new dough nut washer (close coupling washer)will be required,getting the correct one will be easier once the old one is off as they can vary but the screwfix 2 inch washer has worked on many unknown cisterns.
    The metal clamping plate may be corroded away,it may also need exchange.

    A roll of ptfe & a tube of lsx are always usefull to have at hand,if not used they can be returned for refund :D

    Glenne Nelson,do you have the tools to do the job,adjustable spanners,grips,channel lock pliers etc. To fit the large diameter siphon back nut and the smaller overflow & water inlet fittings.

    get all the parts ready and start the job as early as possible in case you have to pop out for more parts ;)
     
  15. Glenne Nelson

    Glenne Nelson New Member

    Erm !! saver bag....anything in the cistern her indoors has put there. I'll have a look and remove. I sprayed WD 40 over the butterfly nuts yesterday. I have ptfe (although unused for 20 years). lsx, I'm not familiar with (will google) and yes, I have all the tools. Thanks guys, you are all bricks.. I think that's how you spell it... I'll keep y'all informed. Of course, my plumber may return my call tomorrow.
     
  16. terrymac

    terrymac Screwfix Select

    As the cistern has to be removed ,you will obviously need to disconnect the water supply ,at the fill valve. You will need a new washer there as well as all the other stuff advised above.
     
  17. Glenne Nelson

    Glenne Nelson New Member

    Thanks, I'll get everything together and start early one morning.
     
  18. Glenne Nelson

    Glenne Nelson New Member

    lkm,.
     
  19. I would definitely fork out for the Dudley two part one. Modern siphons are 8.5" high as opposed to 9 - 10. This means that you don't have to lift the water so high to start the flush. It also means that the cistern will over flow into the pan rather than the overflow pipe (which have been know to leak internally).
     
  20. Glenne Nelson

    Glenne Nelson New Member

    :cool:

    I was asked if I had the correct tools...will these do. the rust shows how long they've been unused. As an avid DIYer, I have many more tools. Everything has been WD 40ted days ago. IMG_8770.JPG
     

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