How to fix a smelly drain

A smelly drain can usually be tracked back to a clogged waste trap. Located between the plug and the waste pipe, the waste trap is designed to hold a small amount of water to prevent anything from leaking back from the pipe – including bad odours! But if your trap is blocked, odours will quickly make their way into your home. Luckily, there are few solutions.

In order to eliminate the blockage and the accompanying smell, you can try to manually unblock the drain, use a plunger or drain snake, or even remove the trap altogether and give it a good clean.

Another option is to use a household product known to unblock drains or remove odours, such as soda crystals, a mixture of bicarbonate of soda, salt and white vinegar or even coffee grounds or natural yoghurt. Of course, you can also buy an off-the-shelf product that has been designed to remove odours or unblock a drain.

Once you've tackled the issue, you just have to try to prevent any bad odours from returning by making sure waste isn't left to build up in your drain.

If you think there is a blockage in your waste trap, a few different techniques can be used to manually unblock the trap without the need for any chemicals.

Using a plunger to clear a blockage

While this method requires a bit of elbow grease, it is also easy and cost-effective. Start by covering the overflow of your sink or bathtub with a damp cloth so that no air can escape. Place the plunger over the plug and fill the sink or bath with enough water to cover the base of the plunger. Plunge vigorously so that the pressure works to clear the blockage.

Removing the trap: an effective solution

If plunging or any other method has failed, it could be that there is an object stuck inside the trap. In this case, the best thing to do is to remove it altogether. Place a basin underneath the trap, unscrew it by hand or using a pair of water pump pliers, remove the item causing the blockage, then reassemble everything, making sure to replace the seals.

Using a drain snake 

It is possible that the blockage responsible for the unpleasant odour is further along in the system. If you suspect this is the case, a drain snake might be your best option. These devices consist of a handle or crank attached to a long metal corkscrew-shaped auger. Insert the drain snake into the plug and turn it so that it catches onto the blockage, then pull it out slowly.

If you're not keen on the idea of disassembling any parts, there are a few effective old-fashioned solutions to try out instead.

Using a household product to unblock a drain

Soda crystals

Be sure to wear protective gloves and safety goggles. Pour a cup of soda crystals down the plug followed by some hot water. Leave the crystals to work for 5 minutes or so, then rinse.

Bicarbonate of soda, salt and white vinegar

Pour a tablespoon of bicarbonate of soda down the plug, followed by a tablespoon of salt and a cup of white vinegar. When mixed, these products produce a chemical reaction that produces effervescence. Leave the solution to work for about half an hour before rinsing with hot water.

Coffee grounds

Coffee grounds have a deodorising effect, but will also help to clean any impurities in the drain through abrasive action. Pour some down the drain and leave overnight. In the morning, rinse well and that's it! Coffee grounds can be used around once a week, but it's important to make sure your drain is otherwise clean and don't go overboard: use too much and you might end up creating a blockage.

Natural yoghurt

The bacterial content of yoghurt can help to get rid of grime and, in turn, nasty smells. Simply pour a little yoghurt down the drain. You should ideally leave the yoghurt for a couple of days before rinsing.

Of course, you can also purchase a ready-mixed product designed to prevent drain odours or remedy them in case of a blockage.

Drain odour prevention

Generally in liquid or powder form, drain cleaning products are designed to break down any food waste and keep your drain smelling fresh.

Drain unblockers

Usually containing sulphuric or chlorhydric acid, these products are excellent at clearing blockages and eliminating odours. However, they should be used with caution as they are often very toxic and harmful for the environment. When using any of these products, be sure to wear safety goggles and a mask, and remember to air out the room.

Once you've dealt with the smell, the best course of action is to try to prevent the issue from coming back. To do so, there are a few basic solutions.

Limit waste build-up

Remove all leftovers from dishes before you wash or rinse them in the sink. Be sure to get rid of any hair in the wash basin, shower tray or bathtub after washing.

These little habits should prevent you from having to deal with odours again in the future.

Use a sink strainer or hair catcher

Another good option is to place a sink strainer over the kitchen sink and install a hair catcher in your shower or bathtub. This should limit the amount of debris flowing down your drains.