How to Fix an Overflowing Kitchen Sink in 5 Fast Steps

By: Diana Rodriguez-Zaba
Updated on: March 20, 2024

You step away for just a minute. Suddenly, you hear gurgling noises. When you look back into the room, you know you’re in trouble. The kitchen sink is filling up with water.

What do you do first?

If you’re lucky, you catch the sink overflowing before it floods the entire kitchen. Still, you need to stop the water, drain the sink and get things cleaned up.

Our team regularly restores homes in the Chicago area damaged by overflowing sinks. We’re here to help with this guide.

Let’s get started!

Taking Control of a Flooded Kitchen Sink

Different appliances and all the sinks, showers and toilets in your home operate on one interconnected plumbing system.

A clog in this network is the most common reason for water backing up in the kitchen sink.

Quickly figure out what might be draining somewhere in the house. If it’s the dishwasher or washing machine, turn it off.

If there aren’t any appliances running, shut off your home’s main water valve.

5 Steps to Unclog a Kitchen Sink Filled With Standing Water

Bail as much water as you can from the sink, and assess the damage. If things look bad, call your insurance agent and start the water damage claims process.

Try one of these five tips for unclogging the kitchen sink, but be patient. It might take several tries or a combination of techniques to get the job done.

1. Check the Disposal

Run enough water down the disposal to allow for safe operation. Turn it on, and let the water and disposal run for a few minutes.

If the flooded sink begins to drain, you know you’ve dislodged a clog in the disposal line.

2. Try Boiling Water

Bring a large pot of water to a full boil. Wear oven mitts to protect your hands as you pour the hot water directly into the clogged sink drain.

If you don’t get results right away, let standing water in the sink cool, and then try again.

Power Tip: Pour half a cup of table salt into the drain before dousing it with boiling water.

3. Use Simple Chemistry

Fizz out the clog by pouring a cup of baking soda down the drain followed by a cup of white vinegar. After the mixture bubbles up and settles down, top it off with a pot of hot water.

4. Grab the Plunger

If none of the above tricks work, it’s time to use the plunger. Make sure there’s enough water in the sink to cover the plunger bell and ensure a tight seal. Minimize splashing by working the plunger with a firm, steady action.

Power Tip: If you’re unclogging a double kitchen sink, seal off the drain that’s clear before plunging the clogged side.

5. Clean the P-Trap

Put a bucket under the curved P-trap pipe below the clogged sink. Detach the trap by removing its coupling nuts, and clean it out with a stiff bottle brush or wire coat hanger.

Power Tip: After cleaning the P-trap, run a plumber’s snake through the exposed stub pipe to clear any clogs that might be further down in the system.

Cleaning Up After Kitchen Sink Flooding

Once you unclog the overflowing sink, water damage needs to taken care of as quickly as possible. Otherwise, you risk long-term damage to floors, walls and cabinets as well as a mold outbreak under the kitchen sink.

  • Thoroughly mop floors, pantries and cabinets.
  • Clean all surfaces with a mild detergent.
  • Position fans to cross-ventilate and dry out the room.
  • Leave cabinet and pantry doors open during the drying process.

The Dangers of Sewage Backing Up in the Kitchen Sink

While most kitchen sink flooding results from clogs in your home’s plumbing system, damaged sewer lines can cause serious problems.

If you think you’re dealing with sewage backing up in the kitchen sink, locate the sewer clean-out line behind the house.

Using an adjustable wrench, remove the line’s clean-out cap to release water pressure. Be careful because this will send sewage out of the pipe and into the yard.

Never try to handle dangerous sewage cleanup by yourself. Bring in a restoration contractor who specializes in biohazard-certified cleanup.

Dealing with an Overflowing Kitchen Sink in Chicago, IL? We Can Help!

tech repairing flooded kitchen
Professional flood restoration specialists take care of overflowing sink water damage by thoroughly drying your property.

We know you can handle most kitchen sink leaks, clogs and floods, but we’re here with expert backup. Our emergency water leak repair services in Chicago and suburbs cover all types of small plumbing problems from kitchen sinks to water heaters.

You can count on us for flood damage and plumbing leak cleanup too. If a flooded sink tries to take over your kitchen, we’re standing by and ready to roll.

Just give us a call here at ServiceMaster Restoration by Zaba: (773) 647-1985

Overflowing Kitchen Sink FAQs

How can I prevent my kitchen sink from overflowing?

Slow or clogged drains cause most kitchen sink overflows. Regularly clean the drain grate. Never pour cooking grease down the drain. Once a week, let a cup of vinegar set in the drain for 30 minutes and then flush with hot water.

How do I unclog a double sink filled with standing water?

Start with the garbage disposal sink. Plug the other drain to minimize splashing. Use a plunger on the disposal sink, and then clear the other sink. If this doesn’t work, bail out both sinks, and pour salt and boiling water down each drain.

How do I prevent clogs in the garbage disposal sink?

If you drop anything but food down the disposal, unplug the unit before clearing it out. Don’t push leftovers down the disposal too quickly. Always operate it with plenty of water, and flush it out for a few minutes after every use.