How to fix bad smells coming from drains and pipes

Posted by: John Temple on 24th March 2023

We’ve all been there – there is an unpleasant smell coming from the drains or pipes in your home; but no obvious blockage or build-up that seems to be causing it. The build-up of dirt residue is often the cause of these odours, but there are other potential causes too. Read on to find out all of the causes of bad smells coming from drains and the best ways to rectify them:


Common causes

The most common cause of a bad smell coming from pipes is the build up of bacteria on the debris inside. When the bacteria feeds on the debris, a hydrogen sulfide gas is released which smell is likened to eggs or sewage. Debris is often the remnants of food, dirt and hair which gets stuck in pipes over time.

The vast majority of sinks have air vents to release gases. If it is a sink that is giving off a bad smell, it may be due to a blocked air vent. The other cause could be a seal not functioning how it should – there is a seal housed in the curved pipe below the sink named a ‘P-trap’ which holds water to stop sewer gases from entering the home. In these cases, it is best to contact our plumbing professionals to rectify the odour issue.

A routine sink clean can help to prevent the build-up of bacteria, stagnant water and in turn reduce the chances of nasty smells.

In the worst case scenario, an unpleasant odour is indicating a blockage. The growth of mould is a main contributor to a clogged drain. This is because warm and wet environments like pipes and drains are a perfect breeding ground for mould growth.


Resolving the issue

The first port of call when faced with a smelly drain or pipe is cleaning it yourself with a top-quality drain cleaner. These can be bought in most supermarkets and online. Always read the label for instructions on how to best use the drain cleaner. There are also drain foamers available to purchase which give a deeper clean of pipes if required.

If bad odours don’t seem to go after cleaning the pipes yourself, or you would just like some expert help with resolving a foul-smelling drain, contact our team today. We can advise the best way to rectify the smell – this may require a plumbing engineer visit to your home to carry out an in-depth analysis of your drains.


Beyond clogged and smelly drains, our friendly team of experts can assist with all of your heating and plumbing requirements. From boiler servicing to the installation of gas appliances and everything in between, we’re here to help.



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