One way trap?

[kaseryn]

Hi.. i have a recurrent problem with blocked sinks in my block and the first symptom is the washing machine filling with dirty water. To stop that happening is there such a thing as a washing machine trap that will prevent backflow?

 

[Agile]

It would appear that your WMC has been wrongly fitted.

It is probably connected directly to a waste pipe under your sink. This is not ideal.

If its done like that then the pipe should loop upwards to the height of the WMC. In addition if it still will backfill then an air admittance valve could be fitted at the top of the loop.

I suggest you either produce a scaled or dimensioned drawing and publish it on here for advice or get a competent plumber to look at it.

Tony

 

[Nige F]

You could fit a Hep V O waste valve .BUT if you mean there are other flats with the same problem in the block.then you`ve possibly got an undersized waste stack....or if it`s just your flat I would get the pipework cleaned and checked for correct installation

 

[ChrisR]

Are you saying that other people's waste water comes back into your washing machine? Are you the bottom flat?

 

[kaseryn]

Hi guys thanks for the feedback. As far as i know its not a widespread problem in the block.. i've had the repair blokes round a little while ago and they whizzed that thing in the sinkhole that shoots out a cable? That did the trick for a few weeks but now the washing machine is filling up with nasty water again. I'm quite sure its sinkwater thats going back into it.. as for diagrams and the like, how about some photo's :


http://www.kaseryn.myby.co.uk/trap.jpg

http://www.kaseryn.myby.co.uk/trap2.jpg

 

[chrishutt]

As agile pointed out earlier, your problem is that the washing machine hose does not loop up as high as possible. Also the design of the trap doesn't help. Is it possible to lower the trap outlet level?

 

[kaseryn]

Dont think i can lower the output.. but if the hose is the problem, why has it only presented a few times in. six or more years?

 

[ABN]

How quickly does you sink drain?

Water tends to follow the path of less resistance. Since the water in your sink is higher than the washing machine outlet if the sink waste pipe/sink trap is blocked then the water will go down the easier route and into the washing machine.

As to why its not happened for the past 6 yrs then that could be down to the gradual build up of scum/hair/decomposed food etc which are now blocking the pipes.

 

[kaseryn]

Ok, i get that.. which brings me back to my initial post really. It's only happening when the sink gets blocked so can i fit something to stop the washine machine being unusable while that happens?

 

[kaseryn]

re: drainage, its not really very noticeably slow.. but the last time it blocked it progressed till it wouldnt drain.. which was when the washer was full really.. of crap water.

 

[ChrisR]

when the sink gets blocked so can i fit something to stop the washine machine being unusable while that happens?

Sure - plumb the wm outlet through its own waste pipe, outside, to a soil pipe, hopper or gulley.

 

[kaseryn]

Anything like that would be a major undertaking, as the services all run into a bricked up stack.. can i get a fitting that wont allow backflow?

 

[ChrisR]

Yes you can, 40mm wastepipe size. If you keep your sink pipe clear though and loop the hose up as advised, you would avoid needing one.

 

[kaseryn]

Well the hose is about as high as i can get it without changing or extending it and until the sink drainage backs up its sufficiently high to keep things flowing in the right direction. As the sink drainage is looking like a recurring theme i want to ensure use of the WM at all times.. so what is the name of the part i need and how much might it cost? Thanks.

 

[longdogs]

Not an expert on appliances but surely there should be some kind of non return valve fitted within the machine that should prevent this from happening anyway? Maybe not?