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Discuss Blocked kitchen sink in the Plumbing Forum area at

  1. Londoner

    Londoner New Member

    The kitchen sink in my second floor flat has always been problematic.

    It's finally given up the ghost.

    The setup is the main sink, rinsing sink and dishwasher. I'm guessing the grey flexipipe is the actual waste pipe? I can't see as it disappears down the back.
    • I've tried plunging both sinks (this usually helps with minor blocks). But this time it doesn't really do much - it just pushes water to the other sink.
    • I've tried a couple of products to unblock the sink with no luck.
    • I've taken off the grey flexipipe in the picture and tried a 6ft rod down it, with no luck.
    • When I take off the flexi pipe, water drains fine from the sink out of the white pipe.
    • When I put water down the flexi pipe alone, it holds water. Is this the problem pipe?
    • I've had the dishwasher running to see what happens & the backs up into the sinks.
    Does anyone have any further DIY recommendations to avoid a call out (money is tight atm).

    Last edited: Jan 11, 2019
  2. richardsimkiss

    richardsimkiss New Member

    Can you get another photo from further round to the right? it just helps a bit to get a better perspective on what's connected to what.

    Where's the washing machine out of interest. You mention dishwasher but the two flex pipes would suggest to me two appliances connected... the waste would/should ultimately drain out the white pipe in the rear left corner.

    It doesn't seem right that the flexes go downwards at the back... they should be above the sink trap other than where they connect to it.
  3. Pickwickpick

    Pickwickpick Top Contributor!!

    The grey pipe is the overflow from the sink. Trace the solvent welded pipe on the left and side of the photo, it goes behind and under the kitchen unit there.
  4. Pickwickpick

    Pickwickpick Top Contributor!!

    Forgot to add, its a bit hard to say from that pic but it looks like the fall might be off and the way the have connected the two sinks together on the solvent welded pipe looks less than ideal but that might be more to do with the phot. If you could take another photo of the solvent welded pipework on the lefthand side, trying to capture more clearly where the pipe from the right hand sink joins the pipe from the left hand sink, it might be helpful.
  5. Londoner

    Londoner New Member

    Thanks for the replies. Not sure if the below helps (took them before I left). Can try and get in there and get some more pics when I get home.

    The washing machine is in a cupboard in the hall with the boiler.

    The only thing connected in the kitchen is the dishwasher.


  6. richardsimkiss

    richardsimkiss New Member

    Okay those pics do help... The grey Flexi pipe at the back is nothing to do with the waste system, so ignore that.

    The grey Flexi pipe on the front is the waste pipe from the dishwasher... That won't be causing your issue.

    You're issue lies somewhere in the white pipework... If both sinks back up/ don't drain then the blockage will almost certainly be somewhere in the pipework behind the unit or further down the line... Which is obviously a bit more of a pain if you're not able to remove/replace pipework yourself.

    The best thing I could suggest before calling someone out would be to remove the trap underneath the main sink (the connection shown in your last photo) and do what you can to rod down the now exposed pipe... Or if rodding doesn't help, a load of bleach left overnight?
  7. Londoner

    Londoner New Member

    Okay, thanks. So I've been working on the wrong pipe for ages :rolleyes::rolleyes:

    So the white pipe that goes into the grey pipe, which then runs behind the boards is the one I need to be working on. I'll try the rod and sink unblocker down there too. It's whether I can actually get the rod down there - there's a lot of curves and all the stuff at the back is solvent welded.
  8. richardsimkiss

    richardsimkiss New Member

    Indeed... if both sinks are blocked then the blockage will be further down the system (i.e. after where the two sinks wastes join together in the back left corner and go down below the units).

    You'll never manage to rod through the trap hence why I suggest removing the trap from the main sink (have a bowl/towel ready!) As that looks like the easiest path to get the rod down (albeit not ideal)
  9. Londoner

    Londoner New Member

    Both do back up. So it seems the problem has been pinpointed.

    Yeah, I've had the trap off already. Bowl is ready and primed.

    Thanks for the advice. I'll get to work on that once I get back from work today. Hopefully the 6ft rod is long enough and can do the job.

    Is bleach enough to dump down there? Or are there any good products I can get over the counter?
  10. richardsimkiss

    richardsimkiss New Member

    Chemicals are rarely the answer in my experience, though I'm currently renovating a bungalow (living on site) and the shower waste is concreted in and slowly blocks over several weeks - I've found thick bleach is just as good as any expensive/branded drain unblocking product! Leaving it overnight seems to work a lot better than a quick few hours before rinsing too.

    Physically unblocking it is going to be a much better solution, the question is just how far down the blockage occurs.

    Best of luck!
    • Like Like x 1
  11. WC1

    WC1 Active Member

    Chemical weapons generally just make it difficult and dangerous to subsequently use mechanical unblocking as they fill the pipe with caustic material which splashes about when you're rodding. Also they can cause heat which can soften the pipe and make it sag. Imo avoid. Take off the trap on the left and rodding down the grey 90 knuckle bend it looks like the trap on the right joins the left and goes out through the back wall behind the left side. Wear goggles if you've put chemicals down it recently. Then go out into the garden and look in the gulleys and manholes to make sure they are running well. Also ask the neighbours downstairs if they have any drainage issues. Let us know how you get on.
    • Like Like x 1
    Last edited: Jan 11, 2019
  12. Londoner

    Londoner New Member

    It seems nigh on impossible to get the rod down these pipes - because they're welded I can't guide it to where I want to go.
  13. Pickwickpick

    Pickwickpick Top Contributor!!

    Yep those rods aren't really designed for the sort of pipe you're trying to unblock, you want a drain auger/snake for these smaller diameter pipes.
  14. JCplumb

    JCplumb Plumber

    Have used this for pipe runs with a few elbows on before with good results.
    Less than £3 - worth a punt.
  15. WC1

    WC1 Active Member

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