Washing machine emptying into dishwasher?

shar46y

OK, I'm not sure but would love it if somebody could help me diagnose the problem whether it is dishwasher or washing machine.

Couple of days ago as I was unloading the dishwasher of clean dishes I noticed there was cloudy water in the bottom. :eek: Thinking there was a clog, I cleaned the filters and ran an empty cycle with dishwasher cleaner - all clean and dry at the end. That evening went to load the dishes and the water was back! Since the previous cycle was fine, I just ran the dishwasher anyway, and again at the end of the cycle everything was clean and dry.

Yesterday evening, I opened the dishwasher and again the water! Then I realised that every time I have found water, it has been after the washing machine was used.

I don't know exactly how the waste pipes are connected as all the appliances are integrated, pipes are all under/behind the units and all was done by the previous owner of the house. There is an outlet pipe plumbed into the U-bend of the 0.5 bowl sink but (until these events) I had assumed it was just for the washing machine - obviously not I guess!

kaya

without a picture or a crystal ball i doubt anybody could diagnoses the fault you describe, it is possible (and more likley) that it is sink water draining back into the dishwasher, if this is a new occurance i would guess that where the waste from your machine connects to your plumbing you may have an anti-syphon valve which has stopped working or has an obstruction preventing it from sealing

shar46y

kaya wrote: »

without a picture or a crystal ball i doubt anybody could diagnoses the fault you describe, it is possible (and more likley) that it is sink water draining back into the dishwasher, if this is a new occurance i would guess that where the waste from your machine connects to your plumbing you may have an anti-syphon valve which has stopped working or has an obstruction preventing it from sealing

Thanks, I have been rooting around in the kitchen cabinets and now see that the 2 appliances are not directly draining into the same spot, although ultimately they do join up to the same pipe which then goes outside. I have tried running water through the sink but this does not cause water to appear in the dishwasher, so am back to blaming the washing machine. I've (hopefully) attached pics.





How do I tell if there is an anti-syphon valve?

premkit

do both black waste pipes join and tee off to outside drain? if this is the case there is the problem. any pic of them both joining or going through the wall or down to an inside sealed drain?

shar46y

premkit wrote: »

do both black waste pipes join and tee off to outside drain? if this is the case there is the problem. any pic of them both joining or going through the wall or down to an inside sealed drain?

Yes, both black pipes are effectively the same pipe, halfway between there's a tee which goes through the wall to outside - unfortunately I can't get a photo of that area because it's in an awkward place.

Should I put drain unblocker down the sink? Maybe that might help?

espresso

shar46y wrote: »

Yes, both black pipes are effectively the same pipe, halfway between there's a tee which goes through the wall to outside - unfortunately I can't get a photo of that area because it's in an awkward place.

Should I put drain unblocker down the sink? Maybe that might help?

The waste pipe plumbing is basically a bodge! How does the water being pumped out of the washing machine know that it should do a sharp left half way along the pipe when it reaches the T junction? It's unlikely that the waste pipe is blocked after the T, so I can't see what drain unblocker would achieve - it's probably always done this.

shar46y

espresso wrote: »

It's unlikely that the waste pipe is blocked after the T, so I can't see what drain unblocker would achieve - it's probably always done this.

Until this week it was fine:huh: surely something must have changed?

blissfulbabe

I had this problem as well - both the dishwasher and the washing machine drained into the same stand pipe with no problems for years then the DW started to fill up with the waste from the WM.

I tried using chemicals, including an acid based drain cleaner. Finally found the problem was the pipe leaving the house (after the u-bend) was at the wrong angle and was completely blocked. I used a coat hanger to clear out the blockage and things have been fine since.

Alias_Omega

I would take the pipe off outside, and have a look. Might find a black sludge like chip fat substance laying in the horizontal bit. As above, use something to scrape it out.

The washing machine is pumping the water out, it will take the easiest route which it is probably backing up in the horizontal to outside, then the remainder of the pressure is shooting up the dishwasher drain pipe.

The outside pipe should just pull off, though you might need to remove some of the wall clamp screws to be able to do so.

The worst i have ever seen was at my nan's house, i think years & years of food remains had blocked half the pipe, about 2 mtrs in length... Yuck..

karl-123

fit a proper washing machine/dishwasher standpipe,
you will get one in there is room,

explumber

could use one of these. placed one side of the tee, that exits through the wall.



McAlpine T28M-NRV 1.5" Inline Non-Return Valve with Top Access T

• Model: T28M-NRV
• Shipping Weight: 0.35kg
• Manufactured by: McAlpine

£9.01 inc VAT