Dishwasher Backing up Into Sink
Did you know that your kitchen sink and dishwasher both drain into the same drainage line? This means that any blockage in this main drainage line can cause water to back up and overflow into your kitchen sink.
4 Reasons Your Dishwasher Backs Up Into the Sink
Kitchen sink clogs typically occur in one of the following four places: the air gap, the dishwasher, the garbage disposal, or the sink. All of which can cause water to back up into your sink when you run your dishwasher. Read on to learn more about why this happens and what you can do to fix the problem.
1. Dishwasher Blockage
A clog in your dishwasher’s drain can cause water to come up through the sink when running the appliance. A simple way to determine if this is your issue is to check if there is standing water in your dishwasher the next time you run the appliance. If there is, then it’s likely that the dishwasher is the culprit and there is a clog or obstruction in your dishwasher’s drain line.
SOLUTION: Check the drain located in the rear of your dishwasher for obstructions and check the drain hose as well for kinks or clogs. Also, be sure to use the correct detergent for your dishwasher as detergent residue can build up and cause a clog as well.
2. Garbage Disposal Blockage
If water is coming up through your sink drain while running the dishwasher, the culprit could be an unlikely cause: your garbage disposal. When is the last time you ran your garbage disposal? If the answer is, “I can’t remember”, then you may want to make sure that the drain is not partially clogged. Alternatively, if you recently had a garbage disposal installed, the drain plug cover may have accidentally been left on. This can cause the water to drain improperly from your dishwasher or sink.
SOLUTION: If you think your garbage disposal may be the problem, turn on the cold water and run the garbage disposal for a few seconds. Also, check to see if the drain plug is still intact and if it is, remove it.
3. Sink Blockage
Kitchen sinks can easily become clogged by food scraps and other debris. This is especially true if you toss pasta, rice, eggshells, grease, or coffee grounds down your sink drain. Similar to a clogged garbage disposal, a clogged sink can not only cause your sink to drain slowly, but it can also prevent your dishwasher from draining properly and cause water to back up while running your dishwasher.
SOLUTION: To remove a clog in your kitchen sink try running the garbage disposal, using a sink cleaner, or using a drain snake.
4. Air Gap Blockage
Air gaps separate the hoses that connect your sink and the dishwasher, which can help prevent water from backing up into the dishwasher. Not all kitchen sinks have air gaps, but if you have an air gap installed in your sink it may be clogged which can cause water to back up into the sink when you run the dishwasher. The air gap is likely located on the top of your sink next to the faucet in order to prevent backflow from your dishwasher. If water is flowing from the air gap, there is probably a clog.
SOLUTION: Luckily, cleaning out a clog in the air gap is relatively simple. Remove the top cover and unscrew or unsnap the inner protective cap. Look inside the air gap for any visible debris. If there is noticeable debris, remove it and replace the cap. More severe clogs may require a bottle brush, which can be purchased from your local hardware store.