By Drain Doctor on 17/05/2016

Today we take a look at the rather pongy issues of stinky sinks!


The warmer weather usually helps draw our attention to pungent whiffs and pongs, which may have been building over the winter. So if you are holding your nose whenever you are using your sink or bath, perhaps you should read on to find out why…


Unpleasant pongs are caused when the ‘trap seal’ is lost. The trap seal is the water seal in the drain pipe under the sink, commonly known as the U-bend. It could actually be an S or a J-bend, but all sinks will have some sort of trap seal.  


The loss of this seal can be caused by:


•    Foreign material such as hair, bits of cotton or string or waste food which gets caught over the bend of the trap. It then absorbs the water and deposits it down the waste discharge pipe. Over time the seal will be lost as the water level decreases.


•    A fault in the trap or incorrect installation may cause the seal to be lost.


•    If a large amount of water is thrown down a sink, such as a bucket of water, the speed at which the water falls and shoots round the bend to the waste pipe breaks the seal and empties the U-bend.


•    If you have a sink which you do not use often, perhaps an outhouse sink, you may find the water evaporates, particularly over a hot summer and this leaves no water in the pipe to create the seal.


•    Other sanitary fixtures which are connected to the same discharge pipe can sometimes cause siphonage. As the water falls down the pipe and passes the branch pipe connected to it, it draws air from it and this creates a partial vacuum which in turn causes siphonage of the trap to take place.

If you have a nasty niff coming from your sink, contact our drainage specialists on 0800 70 71 72 or find a plumber near to you on our Contact Us page