Unclog a Sink Drain

• TASK: Unclog a drain in a kitchen or utility room sink in order to ensure that it continues to function.
• CONDITIONS: Given a sink, access to the drain pipe, a plunger, a bowl or bucket, a pipe wrench, and a wire coat hanger.
• STANDARD: You must be able to clear the clog from the drain pipe.

Identify
The most common way to identify that a sink drain is clogged is by the water that backs up into the sink instead of running down the drain like it usually does. When you see that a sink isn’t draining, it’s time to start going through the steps necessary to clear the pipe.

Activate Erator
Many kitchen sinks are equipped with an erator that grinds up food that would otherwise clog your drain. If your sink is backing up and you have an erator, try simply activating it to clear the clog.

Use the Plunger
If your sink doesn’t have an erator or if it doesn’t clear the clog, the next step is to use the plunger

• Dip the cup of the plunger in the standing water at an angle to avoid trapping air in the cup.
• Place the cup over the drain so that it forms as tight a seal as possible.
• Place the stopper in the other sink drain and place a heavy pot over top of it to keep the force of the plunger is focused on the clog rather than simply being pushed out through the other sink.
• Using slow, forceful movements push the plunger downward 5-10 times to attempt to dislodge the clog.
• Break the seal of the cup on the drain to see if the water will drain.
• If the drain is still clogged after several iterations, it may be time to try the next step.

Clear the Trap
If plunging doesn’t clear the clog, it’s time to remove and clear the trap.

• Identify the first ‘U’ shaped curved pipe at the bottom of the drain pipe below the sink. This is the trap.
• Place the bucket or bowl below the trap so that it can catch the water that will run out from the sink once the clog is cleared. Make sure that your bucket/bowl can contain the volume of the water in the sink or it will run over and cause a mess.
• Unscrew the threadings that hold the trap onto the pipe. This might be possible by hand, but you may also need to use the pipe wrench. Once you begin unscrewing the trap, water will likely begin draining, make sure your bucket/bowl is positioned correctly!
• Once you’ve unscrewed both sides of the trap, dump any standing water into the bucket and clear the clog if it is in the trap.
• If no or only a little water drains into the bucket when you remove the trap, the clog is in the pipe between the sink and the trap. You can use a straightened wire coat hanger to reach up in this pipe to try and clear the clog. Make sure the bucket/bowl is positioned below the drain to catch the water when the clog is cleared.
• If the sink drains completely when you remove the trap, then the clog is somewhere past the trap between the pipe and your main line. You can try running the coat hanger down the pipe to see if you can clear the clog, but if not, you’ll either need to rent a cable auger to reach deeper into the pipe, or call a plumber.

Put it Back and Test
Once you’ve cleared the clog, it’s time to re-attach the trap and test your work.

• Re-attach the trap by screwing the threaded coupling back onto the sink drain pipes. Be sure to avoid cross-threading as this will result in a leaky pipe.
• Turn the faucet on as high as you can to run water through the newly cleared pipe.
• If the water backs up into the sink again, there is another clog somewhere else in the pipe. Repeat the steps from “Use the Plunger” and “Clear the Trap” again.
• If the water runs freely, then you’ve successfully cleared the clog.