Why is My Double Kitchen Sink Backing Up to the Other Side?


Having a double kitchen sink is a great way to make food preparation and cleanup more manageable, but when one side of your double kitchen sink starts backing up to the other side, it can be a huge inconvenience. If your double kitchen sink is backing up, you might wonder what could be causing the issue. Let’s look at some common causes of a double kitchen sink backing up and discuss the best ways to resolve the issue.

The Sink Drain is Clogged

If your double kitchen sink backs up to the other side, the first step is to check for any clogs in the drain. This can be done by looking for any debris accumulated in the pipe. If you find any blockages, you can use a plunger to dislodge them. If that doesn’t work, you may need to call a plumber to assess the issue. A plumber will be able to determine if the problem is within the sink pipes or if more significant issues are present with your plumbing system.

The Garbage Disposal is Clogged

The garbage disposal is usually connected to the dishwasher and sometimes even the washing machine. The most common causes for malfunctioning garbage disposal are a clogged motor, worn-out motor bearings, or something stuck in the blades. To test if your garbage disposal is causing the problem, unplug it and run both sides of the sink separately. If they both drain correctly, you know the garbage disposal is causing the issue. In this case, you should either attempt to repair it yourself or contact a professional plumber to take care of it.

The P-Trap is Clogged

The P-trap is an essential component of your plumbing system underneath your sink. The P-trap looks like a curved pipe with two openings, one for incoming water and the other for outgoing water.

The purpose of the P-trap is to act as a catch-all for debris blocking the drains. Over time, grease, food particles, and other debris can collect in the P-trap and cause a clog. If this happens, it can prevent water from flowing through the drains and lead to a double kitchen sink backing up to the other side.

If you’re comfortable doing so, remove the P-trap and look inside it for any blockages. Be sure to have a bucket ready if water spills out when you unscrew it. However, if you feel uncomfortable doing this, you should contact a plumber to help you out.

The Vent Stack is Clogged

Vent stacks are vertical pipes that allow air to flow into your plumbing system and ensure water can flow freely through your pipes. If your vent stack is clogged, it can cause your double kitchen sink to back up. You’ll need to access your home‘s roof to check for a clog in the vent stack.

Start by checking the pipe running from the roof to the sink. If there are no signs of clogging or blockage, you may have an obstruction inside the vent stack. Then check for a clog inside the vent stack by looking down the pipe from the roof.

If you see any obstructions, such as leaves, twigs, animal nests, or debris, use a plumber’s snake or another cleaning tool to remove them. Once you’ve cleared away any clogs, check the water flow in your sink to ensure it works properly.

The Sewer Line is Clogged

If all other sources of a clog have been eliminated, you may need to check your sewer line for clogs. This is often the case if your double kitchen sink backs up from one side to the other. To inspect your sewer line, you must access the cleanout pipe. The cleanout pipe is typically located near the home’s foundation, usually in the basement or outside. Insert a flexible auger into the drain to investigate any clogs in the line. If there are any blockages, you should be able to remove them with the auger.

Once you’ve cleared out any clogs in the sewer line, run both sides of your double kitchen sink simultaneously to ensure the clog is completely gone. If your sink continues to back up from one side to the other, it could indicate a deeper issue with your drainage system. In this case, it is best to call a professional plumber for further investigation.

A double kitchen sink backing up to the other side is a common and frustrating problem for many homeowners. It can be caused by various issues, such as clogged drains, improper installation, or malfunctioning garbage disposal. By identifying the root cause and taking appropriate action, you can effectively resolve the issue and prevent it from happening again. If you need assistance with your blockage problem, contact the professionals at Marco Plumbing for further assistance.