Adding dishwasher to washing machine waste pipe

24 Jan 2011
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United Kingdom
Hi all,

I am trying to install a dishwasher to the same waste pipe as the washing machine and need some advice.

Currently the washing machine waste goes into a stand pipe/ p-trap arrangement, the trap having compression fittings for 40mm pipe at both inlet and outlet. I figured that I could replace the p-trap with one that has a spigot on like this:
However I failed to realise that sink fitting is different to the compression- pipe fitting at the other end of the trap, so the stand pipe doesn't fit the new trap as it has no threaded end.

My questions are therefore:
a) can/should a dishwasher be attached to the washing machine stand pipe;
b) if so what do I need - different trap, adaptor to stand pipe?
c) should I instead focus on plumbing the dishwasher to the sink outlet with the trap I have (the sink is another metre or so further away)?

Thanks, Mal
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A, Can be yes
B Get one of these, it go's on top of your standpipe.

Mcalpine V33WM

C Personally i prefer wastes onto sink traps rather than standpipes. ;)

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