The dryer I still can connect to the waterproof Xavax but the siphon (DALLMER Concealed washing device siphon HL 400 A) I can not connect to Xavax waterproof. Here, the flat seal seems to be the problem. I have now found the solution to my drain connection (wall): a DALLMER washing device Siameze 1 "combined with a DALLMER Angle-1"! The dual port has built-reflux fuses and the Angle-1 "you can easily connect the hose of the dryer with the smaller diameter, however, the two connecting parts have together about 28, -. Cost Euro (incl. Shipping) - but it works perfectly!