Unclogging a Laundry Sink Drain
Check the other drains in your house to make sure the problem is isolated to the laundry sink. If all other drains are draining normally, then it is safe to assume the problem is only at the one location. If other drains are slow to drain the problem may be bigger than just one sink.
Remove any strainers in the drain and use your fingers to remove any solids that may be sitting at the bottom of the drain cup. After you remove solids, run some water into the sink to check the drain performance.
Fill the drain with approximately 3 inches of water and use a plunger. Place the plunger over the opening of the drain and begin to plunge. If this is successful the water will disappear quickly. If not proceed to the next step.
Place a bucket below the sink under the pipes to catch any water in the pipes.
Remove the S-trap from the bottom of the pipe. This is a portion of pipe that is shaped like an ‘S’, and retains a small amount water to help prevent sewer gas from entering the home. However, they are also a good place for clogs to develop. Remove the S-trap with a pair of pliers.
Clean the S-trap and reattach it to the pipes.
Test the laundry drain by running water into the sink. Water should flow freely down the drain.