Problem with Waste Plumbing For Both Dishwasher And Washing Machine


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Until recently, I had no problems with a washing machine plumbed into the kitchen waste via a standpipe as follows: http://tinyurl.co.uk/cee3 ... standing in for ... http://s28.photobucket.com/albums/c219/JavaJive/Waste/?action=view&current=UnderSink-Before.jpg&refPage=&imgAnch=imgAnch2
From bathroom | | | | Main Soil Stack | | | | | | | | | | | | | | | | | | | | | | | | Washing Machine | | | Sink | | | | | +----+ +-----+ | | | | | | | | | | | +---+ | | | | | | | Standard Sink U-Trap | | | | | | | | | | | | | | | | | | | +---+ | | | | | | | | | | | | | | | | | | | | | | | | | Standard U-Trap | | ||||----------/ /-------------+--------------------------------/ | ||||------------------------+ | +--------------------------------/ | | | | | | +---+ | | To sewer
When I acquired a small dishwasher, I adapted the waste plumbing as follows: http://tinyurl.co.uk/33lv ... standing in for ...
http://s28.photobucket.com/albums/c219/JavaJive/Waste/?action=view&current=UnderSink-After.jpg&refPage=&imgAnch=imgAnch1
From bathroom | | | | Main Soil Stack | | | | | | | | | | | | | | | | | | | | | | | | Dishwasher Washing machine | | | Sink | | | | | | | +----+ +-----+ | | | | | | | | | | | | | | | +---+ | | | | | | | | | Standard Sink U-Trap | | | | | | | | | | | | | | | | | | | | | | | | | +---+ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Standard U-Trap | | | | ||||----------/ /-------------+------------------------/ /-----/ | ||||------------------------+ | +--------------------------------/ | | | | | | +---+ | | To sewer
The discharge flow seems to be adequate in that I don't get *water* coming out anywhere, even when both machines are running together. However, I do get *soap froth* seeping out of the top of the dishwasher standpipe, and all over the cupboard under the sink, as the washing machine empties.
What have I done wrong, and what is the cure?
Any help gratefully received ...
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Java Jive wrote:

http://s28.photobucket.com/albums/c219/JavaJive/Waste/?action=view&current=UnderSink-Before.jpg&refPage=&imgAnch=imgAnch2
http://s28.photobucket.com/albums/c219/JavaJive/Waste/?action=view&current=UnderSink-After.jpg&refPage=&imgAnch=imgAnch1
I hate these ruddy standpipes. NO idea why we use em.
I 'hard wired' mine into the plumbing before a sink trap.
Anyone know why we cant 'hard wire' the washing machines as well?
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I think I prefer the general idea of a standpipe ...
Posting to the group has helped me straighten out my thinking a bit ...
I was thinking that the main purpose of the trap was to stop smells coming out of the sewer, but I now realise they also serve to isolate the appliances waste systems from each other. The more I think about it, the more I think something like this is required (ASCII Art needs fixed font as before): From bathroom | | | | Main Soil Stack | | | | | | | | | | | | | | | | | | | | | | | | Dishwasher Washing machine | | | Sink | | | | | | | +----+ +-----+ | | | | | | | | | | | | | | | +---+Standard Sink U-Trap | | | | | | | | | | | | | | | | | | | | | | | | | | | | Standard U-Trap | | | | | | +---+ | /-------+---------/ | | | | | | | | /---+ | +--------/ | | | | | | | | | | | | | | | | | | +---+ | | | | | | | | Standard U-Trap| | ||||----------/ /---------/ /------------------------+--------/ | ||||-----------------------------------------------+ | +--------/ | | | | | | +---+ | | To sewer

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On 23 Jul,

Why have running traps? I use a standard washing machine trap and standpipe, with a t piece above the trap, and the second input coming in from the side. It has successfully worked for 17 years with two washing machines.
You /are/ using 40mm pipe?
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standpipe,
side.
I already have one running trap, but the one I would have to buy could be a w/m trap. Front-to-back space at the back of the cupboard is limited by the shelf, which might be an issue though ...

Yes, same size as original sink and w/m waste fittings ...
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Because McAlpine make them in response to a lunch they had at the Building Research Establishment.

You can. In fact Franke and others make a sink waste with two spigotty thingies. One for the DW and one for another appliance. A WMC delivers a lot more water so I reckon it's a Good Thing to feed in before a trap on the sink.
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Wonder if the the flow from the WM is drawing air in and it's getting mixed up with WM detergent and pushed round up the DW trap. Try taping off the top of the WM trap and see if it still happens.
Maybe try reinstating the WM standpipe as it was with a swept bend, then tee the DW standpipe in the middle of the WM standpipe.
Wouldn't need any extra bits than what you have already.
cheers, Pete.
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Java Jive said

<snip>
Looks right. Try cutting down on the washing powder.
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I have to be careful which I use, as some irritate my skin, and as a result I suspect I probably use less than most people already. I use Persil Auto, say about a desert spoonful and a half absolute max for my biggest wash, a full set of towels completely filling the drum and requiring a high water level.

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|I have to be careful which I use, as some irritate my skin, and as a result |I suspect I probably use less than most people already. I use Persil Auto, |say about a desert spoonful and a half absolute max for my biggest wash, a |full set of towels completely filling the drum and requiring a high water |level. |
| |> |> Looks right. |> Try cutting down on the washing powder.
The amount of powder required varies with water hardness and many other things.
The general rule for washing powder is to have a thin line of bubbles on top of the water when washing. More then that is just more profit to the manufacturers. The manufacturers recomend what gives them the most profit. |
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Reading water is *very* hard, chalk downs 'n' all that, I suppose ...

Think that's probably about what I do get ...

:-)
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Thanks for all the replies ...
In summary then, would it be fair to say that the general consensus is:
1) As I originally thought, what I did was a legal, approved method which would normally be expected to work?
2) It's going to be either my own or Pete C's suggestions for fixing it?
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Yuk!
Just been having another look under the sink with a view to implementing the possible solutions, and started noticing things I hadn't before, mainly because the bit beyond the LHS is inaccessible behind a built-in corner cupboard between the sink unit and the soil stack.
The most important horror is that, courtesy of the (lack of) workmanship by whoever installed the current sink plumbing, there is no fall between the sink and the main soil stack. In fact, if you look carefully, you can see this in both pics, where the weight of water in the trap is pulling the whole thing down in the middle, so the fall is actually slightly reversed!
This in itself is bad enough, though by itself wouldn't be so bad for most modern convenience food cooking, especially as I'm also vegetarian, so there is less solid grease and and more liquid oil going down the sink, but I also happen to prefer traditional tea from a pot, and have always been in the habit of flushing the leaves down the sink. (I've been doing this for 50+ yrs with no real problem up til now, as long as sufficient water is used - but partly in the light of the drought I've been drinking less tea and more coffee which uses less water, and has the added bonus that the grounds are contained by the filter papers and so can be thrown away instead.)
So I'm now wondering if part of the problem might be that tea leaves and other sink gunge is all washing back into the running trap for the standpipes and partly blocking it. I would have thought that the flow from the washing machine would have tended to keep it clear though.
Thirdly, I'm not sure I was right about the Persil Auto, it's the auto bit I'm unsure of, and as I put the stuff in a plastic container and recycle the box, I can't check back. I'll have to check when I'm next in the supermarket. I think it's this one, though I remember it being as being a similar blue packet but with some yellow around the top of it. http://www.persil.com/persil_products/pfam_non_bio /
So potentially I have a situation of reduced flow leading to more gurgling and churning about of a non-auto powder in the washing machine standpipe, which might explain the excessive froth production in the system, which, because there is no individual trap for it, can then back up out of the dishwasher standpipe.
As a start, I suppose I could try seeing if blocks of wood under the pipes and adjusting the mountings to produce some fall would make any difference, but it's beginning to look like a second trap is required ...
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Well, after endless hours playing jigsaw puzzles trying to fit potential solutions into the space while not fouling or obstructing access to things like the taps and the traps, I eventually settled on one of these in the dishwasher standpipe: http://tinyurl.co.uk/vhfl ...standing in for ...
http://www.speedplumb.co.uk/40mm-hepvo-hygienic-self-sealing-trap-p-1573.html I didn't have room for the 300mm recommended standpipe length above it, only about 140mm, but it being a small dishwasher I reckoned and hoped it would work, and I was right. However, I originally bought a second one for the washing machine as well, and I don't think I want to try less than the recommended clearance with a pump as strong as that, so I'll try and get my money back on it, as they were quite expensive - 11.37 + 2.27 + vat. Annoyingly, the recommended clearance was *inside* the leaflet, so I had to open one of the packets to find out about it.
I've now done a dishwasher cycle and one and a half washing machine cycles without any leaking whatsoever, so while I still hesitate to say that it's definitely fixed it's beginning to look that way ... I guess a pullover cycle with Dreft will be the ultimate test, but that will have to wait until I start wearing them again in the Autumn ...

by
I've now corrected that as far as the geometry of the cupboards would allow without major surgery. It's probably still a little too low, but at least it's in the right direction now!

The running trap stank to high heaven and its throughput was partly blocked by gunge, but I suspect washing machine gunge, not sink gunge as I had feared.

Still haven't checked this out ...
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