Insinkerator food waste disposal leaking?

16 Jun 2006
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United Kingdom
Hi all

A customer mentioned that he occasionally notices water in the cupboard housing of one of his two kitchen sinks. Both have Insinkerator waste disposal units.

It turns out that they have dishwasher inlets, granted, pretty high up, but the units are not supplied with blanking plates for the inlet.

see: number 12 on the PDF

Has anyone else come across this being a problem? If yes, can you recommend a suitable blanking plate?

Thanks in adavance.
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See step 6 of the install manual.

There should be (was, may still be partly) a knockout seal in that dishwasher inlet. If someone has removed or disturbed it it may leak, I guess?.

You'll need a 'bung' to fill the hole and some rubber hose and clips to retain it. (Washing machine hose and clips may do it, or automotive type hoses?) Check the knockout seal has been fully removed - it won't do the mechanism any good if left inside it. is the official connector for a w/m or dishwasher hose to the disposal unit.
Thanks mate.

I don't think that the fitters would have knocked the knockout out (unnecessarily). Perhaps the BG plumber was incorrect about that being the source of the leak.
Needs a look see to find out. A plastic bag and rubber band round the outlet will soon prove it's from that orifice?

The common places to leak (from memory of when we had one) are the interface of motor/housing on the sink fixed plate and the waste outlet seals.
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I think if the plug was missing it would be more than an occasional leak. But you never know...
Missing perhaps yes. But if only partly knocked out, perhaps less or only when excessively filled...

This YouTube video has a cutaway view of one with the (black) appliance inlet near the top.

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