Question for Plumber - Dishwasher drainage

Any plumbers hang out on OzB??

Our dishwasher has a pipe connected to under the sink for the waste drainage. Fairly standard.

It was blocked the other day by a pine nut (grrr). Anyway upon me taking the drainage pipe off the sink waste pipe to clear the pine nut, I noticed the hole is really small, say the size of a pencil…. half a cm? Is this a manufacturing fault or is it designed to be really small to maintain pressure or something? The hose and pipe connection is say 1.5 or 2.0cm diameter but the drain hole iself is much much less.

1) Is this normal or just shoddy manufacturing?
2) If not, can I simply drill a larger hole that is more in line with the size of the tubing to hopefully avoid little objects like a pine nut blocking the hole? Will this cause any potential backflow issues or something from the sink into the dishwasher?

Thanks

Comments

  • Last time I fixed the drain pipe of our dish washer, the tube ( exit ) was the size of your pipe connection 1.5-2 cm. Are you maybe looking at a very ill sized washer?

    • Thanks for the feedback.

      Nah its the actual plastic of the drain pipe from the sink. Off that is the little dishwasher connector but the hole (you would think is the same size as the dishwasher connector tube) but its only a fraction. A pine nut got jammed in the hole it's that small :P

      It just looks odd so thought I'd ask before I start drilling a bigger hole and causing some other issue.

      • The installer probably just got lazy and used a small drill or other hole making implement. Should've been widened from the start - go for it.

        • It's a single piece though. Surely a plumber wouldn't have to drill the hole? I'll take a photo :p

        • +1

          @Skramit: they have a baffle when new to prevent water coming out.

  • +1

    Are you talking about a Y-tailpiece that the dishwasher (or washing machine) drain pipe connects to?

    The Y-tailpiece is normally sealed and only drilled open when an appliance is connected. It's possible that the installer used a small drill bit. You can widen it, if you like … but there's no benefit, if the dishwasher is working. Even if your pine nut goes through, something else could block it later.

    • Ah that makes sense. The plumber that installed it was a total idiot and buggered up a couple of other things like not knowing how to install the tap properly.

      I might drill it a bit bigger though as it's properly small and will no doubt get blocked again by something small.

  • the hole is really small, say the size of a pencil…. half a cm?
    The hose and pipe connection is say 1.5 or 2.0cm diameter but the drain hole iself is much much less.

    please help me understand. how does one fit a hose in a hole half its size?

    • Google Y-tailpiece.

      The hose connects on the outside of the Y-tailpiece.

  • +1

    Yeah what sp00ker said is right, if you put too big a drill in that pvc inlet it's easy for drill to bind and crack inlet.

  • +1

    Just drill it bigger, when I did it, I drilled it so the hole is smooth and flush with the inner diameter of the tube.

  • One of the plumbers forgot to drill the hole into the y piece. Took off the fittings and just went to town with a Dremel.

    Problem solved.

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