Washing machine outlet TO Cold water overflow outlet.

14 Sep 2011
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United Kingdom
I stay on in a flat on the first floor. We were wanting to have a dishwasher for ages but due to lack of space in the kitchen , it wasn’t possible.
Now we have decided to replace the old conventional gas boiler( long due ) with a combination one. The cupboard holding the cold water tank, electric water heater (storage) tank etc is going to be empty. This cupboard is in the hallway and not in the kitchen. This cupboard has cold water/hot water inlets , electricity as well as an cold water tank overflow pipe (all because of the old central heating system elements mentioned above).

We were planning to move the washing machine into this space, and fit a dishwasher into the space where the washing machine was in the kitchen(I hope it should not be a problem to replace a washing machine with dishwasher ).

Now when I plumb in the washing machine, I already have water and electricity. My question is can I use the cold water tank overflow pipe as a drainage pipe for washing machine?
Because it’s a flat and everything is concealed. I do not know where the overflow pipe from the cold water tank goes.

This cupboard is besides the bathroom and I know the pipe comming from overflow ( a plastic grey pipe, probably an inch thick) goes behind the bathroom sink and somewhere near the big black cast iron waste pipe. But I couldn’t bend enough to see where it actually goes..

Can anyone suggest if I can use this for w/m drainage? If this works I can actually move the washing machine myself..

Kindly suggest

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The cold water tank overflow usually goes outside through a wall where you can see it dripping and causing a nuisance, and not into a foul water drain. It's also usually 22mm pipe, whereas 40mm is required for a washing machine.
The washing machine waste should discharge through a trap into a foul water drain.
In short, your old overflow pipe is completely unsuitable.
Thanks Echoes

I understand what you say. Now I have tried to find a work around and there is a bathroom sink drain pipe that i can see near by which i can connect to .

The drain pipe goes and joins the main drain pipe. I guesss it would be ok to let the w/m drain connect to this?

Also is there any self cut system which can allow me to pipe my washing machne outlet (comming from the standpipe ) into the batrom washbasin drain (descending from the trap). The lack of space behind the panelling wll make cutting and joinign difficult.

Thanks again for your comment..

Tushar, if you can access the pipe you are talking about, could you fit a compression 40mm swept 'tee' coupling, plus a McAlpine WMF4 fitting?
Best google these as I'm too thick to post links......
John :)
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Hi All

Thanks for you help.
Finally managed to get this done. Used the self cutting thing from Wickes. Although used my own washers (designed out of cycle tyre tube) as the original ones were too rigid. Did keep dropping the nuts into this very narrow space behind the bathroom . Ultimately had to stick the nuts to the bracket using a quick dry glue and tighten the bolts from the top. Got a few burns from the hot water pipes while doing so.

Overall Dishwasher in place (wife happy) , Washing machine in the new utility cupboard which now has been cleaned , a new laminate floor, and shelves .

Thanks for your help..

PS: It took only a few hours to do it. The reason it took so long was I was waiting for a good deal on Dishwasher ;)


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