Combined Dishwasher and Washing Machine Outlet Problem!!!

[Jasonfo]

My washing machine outlet pipe was attached to my kitchen sink waste pipe and worked fine. I recently installed a Dishwasher, and managed to use a Y attachment to feed both waste pipes from the Washing machine and Dishwasher into the Kitchen Sink Waste Pipe, just above the U bend.

It seemed to be working until I realised all the Dishwasher Water was landing up in my Washing Machine! Washing Machine empties fine and doesnt effect the Dishwasher... What went wrong and how do I fix this???

 

[kevplumb]

make sure the hose rises above the level of the connection

 

[Jasonfo]

Both pipes rise above the connection. Should there be some type of single flow valve that I can attach?

 

[kevplumb]

if your hoses are above the level of the connection to drain
1 water dosent flow upwards
2if its running into another appliance why isnt the sink filling ?