Plumbing question; washing machine drain

masturbidder, Feb 25, 6:22am
NZ plumbing question; can a washing machine drain hose be connected to the under-sink trap, similar to a dishwasher?
kateley, Feb 25, 6:46am
x1
yes, I got the plumber to do just that to mine when he was here last. The fitting is quite similar to the dishwasher fitting. He needed to make a hole in the side of the cupboard to poke the hose thru
tweake, Feb 25, 7:32am
the catch is you need a vent hole. typically an overflow of the basin or just remember not to put the plug in the sink.
otherwise it will siphon the water out as fast as it goes into the machine.
lythande1, Feb 25, 8:43am
That's how mine is. vent hole? No you don't. Vents out of the sink plug.
tweake, Feb 25, 8:52am
you can just use the sink plug as the vent, until the day you use the the basin or the plug hole is blocked.
ideally the basin should have overflow which doubles as the vent.
flagheaven, Feb 25, 10:27am
I was sure the top of the drain pipe had to be same heitght or HIGHER than the HIGHEST water level for the machine
tweake, Feb 25, 11:49am
x1
quite correct i forgot about that. thats a good one to watch especially if the hose is a bit short.
johotech, Feb 25, 1:14pm
masturbidder, Feb 25, 1:57pm
That has the right connection for a dishwasher but I am looking for a larger connection for a washing machine hose. Common in Europe but I can't find one here and wondered if the NZ plumbing regs allowed them.
johotech, Feb 25, 2:34pm
You can use a standard vented trap like this.
http://www.dux.co.nz/product/40mm-compact-vented-telescopic-trap/ Then between the top of the trap, and the sink connection, you add a TEE like this. http://www.dux.co.nz/product/40mm-adaptor-tee/

From that Tee, you come out with 40mm pipe to an elbow, the upwards in 40mm pipe, to as close under the bench as possible, leaving enough space to put the washing machine drain pipe in the top.
supernova2, Feb 26, 6:07am
Here is how is should be connected up. The wash machine drain goes into an open standpipe #8 in the drawing.
www.robinhood.com.au/product_downloads/Supertub_ST6001_Parts_services.pdf

Thats s supertub but the same layout applies with any sort of tub. A plumber will sort it in a few minutes.
kateley, Feb 26, 7:07am
Here's what the plumber put under my tub. It's quite dark in that cupboard so I hope you can see it ok
https://trademe.tmcdn.co.nz/photoserver/full/737444569.jpg
supernova2, Feb 26, 3:02pm
Was that for a Top Load or a Front Load?
Or perhaps the plumber didn't read the washing machine instructions.
supernova2, Feb 26, 3:09pm
masturbidder, Feb 26, 4:31pm
Ah yes that is the trap I was looking for with the bigger connection for washing machines, although I believe it should also have a vent or air valve on the top.
But the NZ standard only shows dishwashers connected that way and clothes washing machines with a standpipe, so I was not clear if it is legal here or not.
johotech, Feb 26, 5:21pm
All those diagrams including the acceptable solution are pretty much what I described with the Tee in#10 above.
And putting it into a standard dishwasher connection on a vented trap will work just fine as well. It will just drain slightly slower.

The main thing is to make sure that the drain pipe goes right up under the bench, before coming down onto the drain connection. Usually using a hook bend like this.
https://www.mrappliance.com.au/0180200001-washing-machine-drain-hose-hook-simpson
toni265, Dec 18, 1:52am
You are very helpful Johotech. 😎