Why Does Your Kitchen Sink Smell? (& How to Get Rid of It)

A kitchen sink that smells can put anyone off their food.

Finding out what’s causing it and fixing it are the first priorities. 

After that, take steps to make sure it doesn’t happen again!

In this article, we show you how.

Where bad kitchen sink smells come from

A build-up of debris in your pipes

This decays and the smell rises through the pipes.

And if the sink smells like rotting food, then you have a build-up of debris (food, fats and oils) in your pipes. 

And if the sink is blocked or water is draining slowly or not at all, debris is even more likely to be the cause.

No water in the U-bend

Smells come up from the sewer pipes. Leaks in your U-bend or water evaporating in hot weather can cause this.

If the sink smells like rotten eggs, you have sewer gases escaping into your home due to a problem with your U-bend.

Mould

Sink pipes(especially U-bends) provide good conditions for mould to grow. It can thrive in the dark, moist, and nutrient rich environment. When it appears, you might notice a musty, sour smell. This might smell like old cheese, an old damp cloth, or even soil - it varies.

How to stop the kitchen sink stink

DIY drain cleaning

Boiling water

If the blockage is caused by a build-up of fats and oils, pouring boiling water down your drain could be all you need to do.

• Fill up the kettle or a pan with water and bring it to the boil
• Slowly pour it down the plughole, being careful not to splash yourself
• Wait 5 minutes
• Run the hot tap to force the oil to flush away

Don’t do this more than one or two times. Most U-bends are made from PVC and might be damaged by repeated contact with boiling water. 

White vinegar

Vinegar is a popular cleaning product as it is cheap, readily available and can conceal odours to a degree.

• Pour half a cup of vinegar down the plughole
• Leave it to stand for 30 minutes, make sure you don’t use the sink during this time
• Run the hot water tap to flush the pipes.

Baking soda and vinegar

You may need more power to shift the blockage. This could be because, for example, the build up has hardened. 

If so, try mixing vinegar with baking soda for a deodorising combo.

• Step 1: Pour half a cup of baking soda down the plughole. Pour it slowly so that it goes down the drain instead of sitting in the sink.
• Step 2: Now pour a cup of vinegar down the plughole. You should hear it fizzing and see it foaming.
• Step 3: Leave the solution to stand for a few hours. Make sure you don’t use the sink during this time.
• Step 4: Pour boiling water down the plughole. This will flush away any remaining debris.

Chemical drain cleaners

You can find chemical drain cleaners in most supermarkets and DIY shops. 

You can choose between two drain cleaners types:

Bio-enzyme drain cleaner 

This works by using enzymes to “eat” the food and remove the blockage. 

This is eco-friendly and non-toxic. So, it’s ideal for avoiding the environmental impact of pouring chemicals down the drain.

A ready-made drain cleaner

This will use chemicals to clear the blockage and remove the smell. 

As these contain chemicals they can be dangerous. 

It’s important to follow the instructions on the packaging when using chemical cleaners.

Fix problems with the U-bend

The U-bend is your first line of defence against sewer smells. This is why it is sometimes known as a sewer gas trap. 

If the methods have failed, it might be time to check the U-bend. 

If it smells like rotten eggs, there is a good chance your U-bend is to blame.

If you’ve been away

The U-bend needs water to work effectively. So, if you have been away and you haven’t used your sink for a while, the water in your pipes may have evaporated. 

All you need to do is run your taps to refill with water.

U-bend leaks

Another potential problem is a U-bend leak. Check under your sink for signs of a leak. 

If you have damp patches under your sink, you may need to tighten your U-bend’s nuts

U-bend blockages

If there is an obstruction in the U-bend, you will need to remove the U-bend and clean it with a wire brush.

If you notice a lot of build up of mould or oil, etc., you can leave the U-bend to soak in bleach for 10 minutes before re-attaching it.

Preventing future kitchen sink stinks

Once the smell in your sink has gone away, you’ll want to take steps to stop it from happening again. Try the following to keep odours away:

• Use a drain screen. This prevents large pieces of food going down the plughole
• Don’t put oil or grease down the plughole. Instead, pour them into an old bottle that you dispose of in your bin.
• Pour boiling water down the plughole occasionally. This will help kill any bacteria. Don’t do it more often than once a month - over time it might damage your PVC U-bend.
• Pouring baking soda down your plughole once a week. This is especially useful to do before you go away.

Other kitchen smells 

Your sink might not be your sole source of bad smells. 

Washing machine smells can be similar to sink ones. So can dishwashers, ovens and even air fryers if they aren’t cleaned well.

Sometimes a general spring clean is the best way to ensure your kitchen smells great 

Need to call in the professionals?

If you have tried everything above and you still can’t get rid of the bad smell from your kitchen sink, it’s time to get professional help.

With the home cover from YourRepair, you’ll be covered for everything from your boiler to your kitchen sink.