Kitchen sink won’t drain: 8 different ways to fix it

If your kitchen sink won’t drain, there are several ways to unblock it without calling a plumber. Many of them don’t require tools or even a plunger. Here are the most common ways to fix a blocked kitchen sink.

Kitchen sink won’t drain – why?

A blocked kitchen sink is usually caused by fats and oils. They go down the drain as a liquid, but solidify in the pipe. Over time, they gradually narrow the pipe before blocking it completely. Coffee grounds will do the same thing.

You should avoid letting any food particles go down the drain, but especially these two things. Throw away coffee grounds and used cooking fat in the household waste. Leave grease in pans and trays to harden, and then scrape it into directly the bin.

Kitchen sink won’t drain – 8 different ways to fix it

Hot water

In some cases, hot water alone may be enough to shift the blockage and get the water moving again. Don’t use boiling hot water straight from the kettle though, as the pipework is usually made out of plastic and this could damage it.

Volume of water

Put the plug in the sink and fill it up as high as you can, right up to the overflow. Then, pull the plug out. The weight of all the water may be enough to push the blockage out the way.

Kitchen sink won’t drain – use a plunger

Make sure that there’s at least an inch or two of water in the bottom of the sink. This helps the plunger to keep an air-tight seal over the drain.

If you have a double sink, you’ll probably find it much easier with another pair of hands to help you. Put a plug in the drain of the other sink, so that your plunging goes down into the pipes and not simply back out the other drain. The second person can press down on the plug to make sure it stays in place, and should cover the second overflow, if there is one.

Cover the main overflow with one hand, and with the other, plunge vigorously for a minimum of 60 seconds, taking care to maintain the plunger’s seal over the drain.

Lift to check if the water drains away, and repeat the process if it doesn’t.

Chemical drain unblocker

There are plenty of chemical drain unblockers available which you can buy from your local supermarket or convenience store. While the instructions for each individual product will vary, they generally work on the same principle: bail out as much water from the sink as you can. Pour the drain unblocker directly into the drain, and leave it for a few hours. The sodium hydroxide dissolves the hardened grease and fat which is causing the blockage.

Drain blaster

As the name implies, a drain blaster uses compressed air to blast the blockage out of the pipe. Pump it up in order to pressurize it, put the nozzle over the drain to make an air tight seal, and then pull the trigger.

Here’s a great demonstration of a drain blaster in action:

Coat hanger

You may be able to use a wire coat hanger to lift the blockage back out through the plug hole. Simply bend it into a suitable shape with a small hook at the end, and try to lift it out. Slide it down the side of the pipe in order to avoid pushing the obstruction further down the drain and out of reach.

Coat hangers can be a really effective tool for removing strands and clumps of hair in the bathroom, like in the shower drain or bathroom sink.

Open the trap

One of the most effect ways to fix a blocked kitchen sink is to open the trap and remove the obstruction from the trap and/or the pipe.

To do this, you’ll need a bucket or another large plastic container and an old towel. You may also want to wear rubber gloves.

Bale out as much water from the sink as possible, and place the bucket under the trap. Slowly unscrew the plastic nuts, letting the water drain into the bucket.

In most cases, you should be able to open the plastic nuts by hand. If they’re really tight, use an old rag or cloth to get a better grip. Take care not to lose any of the rubber washers inside the nuts.

Inspect the pipe and trap for any debris, and throw it away in the household waste – don’t flush it down the toilet or wash it away in another sink. Reassemble the trap, taking care not to forget the washers.

Drain snake

If your kitchen sink still won’t drain, it’s time to bring in the big guns. Every plumber will have one of these in his van.

To use a drain snake, carefully insert it into the drain to the point where you believe the blockage is located. You can help the snake go round any corners in the pipework by twisting it as you push it.

Once you’ve inserted the snake as far as is necessary, push and pull the snake and rotate it by the handle for a few seconds in order to shift the blockage.