Washer pumping out, level in sink rises and overflows ???

[goz666]

As the title, McAlpine waste under a one and a half bowl sink with one spigot for washing machine. If the sink is full of water and the washing machine drains, the level of water in the sink rises and overflows all over the kitchen floor. Waste trap, overflow pipe, and all pipework has been tested and is clear. Machine has been there for years, no pipework changes or anything recently and it's only just started happening recently.

Any thoughts ???

 

[lame plumber]

then you have a blockage somewhere if nothing has changed, strip out the pipework that comes apart and clear out all the grease build up you find.

 

[goz666]

then you have a blockage somewhere if nothing has changed, strip out the pipework that comes apart and clear out all the grease build up you find.

Done it LP, stripped out the waste, the overflow, the pipework right back to the drain outside is all clear. Fill the sink to the top and take the plug out it drains really well. Have removed the washing machine spigot and checked the washing machine hose, all clear. I'm flummoxed as they say !!!

 

[lame plumber]

dont leave the sink full then when using the washing machine.

 

[plumben]

Is the pipe work air locking, blocked overflow or main vent on the drain