Originally Posted by Jonathan Pearson

Cordless Crazy wrote:
I have seen a lot of posts about how to plumb in both a dishwasher
and a washing machine, before and after the sink trap.

What is stopping me installing the following:

1. a simple shallow bottle trap underneath the sink to make use of
the cupboard space http://tinyurl.com/jubtf

2. the 2 appliance waste pipe connect after the trap using
http://tinyurl.com/jn25n

3. a running trap is then installed down the run, to potentially stop
drain smells coming out of the appliances http://tinyurl.com/geiz

Would you actually need the trap below the sink if I have a running
trap further down the run?

All you need is one of these http://www.plumbworld.co.uk/430-465 to replace
your old trap - wickes (or is it B&Q WH) sell them - you connect the WM to
one and the Dishwasher to the other (using hose clips) - to stop smells /
one draining into the other - you make sure that the WM / Dishwasher tubes
are looped over a high point (above the level of the plug hole) - there
should be a diagram on the packet of what to do

Jon