Why does my drain smell?

Start with where the smell is strongest

A smell confined to one sink, shower or floor drain can have a different cause from an odour noticeable across several parts of a property. Identifying where and when it appears helps narrow down the likely source.

Simple causes can be local

Food residue, grease, soap and other organic material can build up around wastes. A little-used fixture can also lose the water seal in its trap. These are different from smells associated with slow drainage, gurgling or wastewater backing up.

When to suspect a drainage issue

Persistent smells alongside recurring blockages, slow drainage or unusual water levels can justify further investigation. Defects, restrictions or ventilation problems may need professional assessment rather than repeated cleaning.

If other warning signs are present

If the smell is accompanied by an active blockage, start with our blocked drain guidance. If the problem repeatedly returns, a CCTV drain inspection may help establish what is happening.