A stubborn stain, odor or even a clog can quickly turn any sink into a nuisance. Clean drains regularly to prevent odors. If you find water no longer drains properly, you can use a quick do-it-yourself fix to have your sink working properly in no time.
https://letsfixit.co.uk/wp-content/uploads/2014/04/12.jpg
Step Four
Wrap a heating pad around the trap pipe under the sink if you know your drain is clogged with grease from cooking. Turn the heating pad on to warm up the pipe, then run hot water through the drain until the grease clears.
https://letsfixit.co.uk/wp-content/uploads/2014/04/42.jpg