On 2013-08-29, Tim Watts wrote:

On Thursday 29 August 2013 12:15 Adam Funk wrote in uk.d-i-y:

I need to rearrange some of the plumbing under the kitchen worktop so I
can push the appliances back further in the slots, & I have a few random
questions about the input & output.

We have a cold-feed-only washing machine in place & a cold-feed-only
dishwasher on order. There are 2 cold connections & 1 hot one; the
hot one has never leaked yet, but I'm a little nervous. Is there a
secure cap I can put over the unused hot connection?


http://www.ebay.co.uk/itm/121145339836

3/4" BSP cap with washer. Available in most fine plumbers merchants and
maybe even B&Q.

Excellent, I'll probably use that.

Or should I just
remove it & cap the hot pipe off because cold-and-hot-feed appliances
are very unlikely to appear again?

That would also be a safe bet. I have not plumbed hot to my machines.


What do I need to do (apart from turning the gas off) to make it safe
to solder a joint on a copper water pipe a few cm away from a gas
pipe? Or should I just use a compression fitting?

If you are not near a gas joint (that teh heat could disrupt or melt), no
major precautions are necessary beyond standard good practise - but I would
turn of the gas anyway.

Use a heat shield mat - which you want to do anyway to protect the wall.

I have one of those, & meant to mention it, but it disappeared when I
was rearranging those sentences!


But a compression joint would be just as good if soldering near gas makes
you nervous. Or even a push fit end cap.

The two waste pipes currently meet at a T above the kitchen floor; the
merged pipe goes under the floor then runs under the kitchen and
through the wall, where it opens over a drain. I haven't been under
the kitchen floor in a long time, & I can't remember whether there's a
trap in there.

I plan to change it so two waste pipes both go vertically down through
the floor and meet underneath, then run to & through the outside wall
(using solvent-weld). Do I need separate traps for each pipe?

No. I have a combined trap for 2 machines. However my trap was made out of
bits of 50mm solvent weld plumbing with screw caps on tees at one top and
one bottom bend to enbale access for unblocking.

I'm not 100% sure what you mean but I think it's something like this
(where XXXs are threaded caps)? If so, I like it.


in
| |
| | |XXX|
| | | |
| | | -----
| | | out
| | | -----
| | | |
| | | |
| ----- |
| |
| --------|
| |
|XXX|


So if using one trap make sure it can take the flow of 2 machines at once
(sod's law says they will align at some point!).

Well, I've been running a washer-dryer & a dishwasher through the
existing set-up, which I'm sure has at most 1 trap, for 10 years.