washer backs up into laundry tub
#1
I just replumbed a laundry room with a laundry tub and a separate laundry drain. The laundry drain is connected to the same line as the laundry tub drain with a wye-pipe. Both have traps at about the same height. This is an old house so there is no vent pipe connected. When the washer drains, it backs up into the laundry tub. It only fills about 1" of water in the bottom of the laundry tub before the washer empties and the tub can then empty. Is there a quick fix for this problem?