Drain Hose

• One possible culprit is the drain hose on the washing machine. If it is clogged, the nearby sink will be affected because the water will not drain well from the washer. Unplug the washing machine, and disconnect the drain hose from the washer. Check the inlet screens for debris or lint that might be causing a problem, and clean out out the screens, using a clean cloth or small brush. When reconnecting the drain hose, make sure the hose is straightened out to prevent kinks or bends from occurring.
  
  

Drain Standpipe

• Another source of drain problems with a washing machine and the nearby sink is a standpipe that is too high or too low. If the standpipe is too low and the drain hose is positioned less than 20 or 30 inches above ground, water flows into the washer but then siphons right out and into the drain system. If the standpipe is too high and is positioned more than 96 inches above ground, the water cannot flow out of the washer and reenters the washing machine, creating a drain blockage. Set the drain hose and standpipe between 30 and 90 inches above the ground for effective draining.
  
  

Clogged Sink Drain

• It may not be the washing machine at all that is causing the sink to bubble when the washer empties. If the sink drain is clogged, then water flowing through the household plumbing as the washing machine drains will cause the drain to bubble up. Clean out the sink drain, and look for any obstructions in the drain that need to be cleared.
  
  

Clearing the Drain

• To clear the drain in the washing machine and resolve the problem, disconnect the drain hose and hold it up while pouring 1 qrt. of water into the drain. The water should flush the drain to clear any obstructions. If it does not, reconnect the drain hose and contact the washing machine manufacturer for help.