This is the HINTS page for SINKS and BATHS BLOCKAGES PROBLEMS.

Obviously this is related to the TAPS HINTS page, but this is more to do with the drainage side (U-BENDS, TRAPS, OVERFLOWS and BLOCKAGES).

NOTE: serious blockages that are affecting the whole house drainage system (toilets, all sinks and bath), may be caused by blockages in the large soil pipe leading to the outside drain. These will need the services of a specialist drain cleaning service, unless you happen to have a proper “rodding kit” and know how to use it, and know the correct points where to “rod out” the blockage. Check 118.com for your local specialists if you need one.

The following picture is of a 40mm U-BEND (trap) that is suitable for a bath. This particular one has a movable section, so that you can (if you have room), point the draining/cleaning plug towards the bath panel, and the other part can be moved to point towards the outflow pipe. Basin traps are similar, but use 35mm pipework.

Over time these traps can get clogged with debris, hair, and soap scum. They are fairly easy to remove and clean. Just ensure you have a bowl or container of the correct size to go underneath to catch the water in the U-bend part when you undo it. It is best to wear some eye protection un case any chemicals you may have used to unclog it are still present. Once you are certain that the trap is clear and clean, replace it, check that everything is tight, and check that no leaks are present when running water through. If there is still a slow or blocked flow, then there may be a blockage further down the waste pipe. There are various chemical unblocking agents available from most supermarkets, DIY stores, and plumbers merchants etc.If you do not have any at hand, you can always try briskly puring a kettle full of hot water down the sink or bath plug. If this does NOT unblock the pipe, you can try the old and trusted tool, the PLUNGER. Get the largest one you can find, as the larger the rubber plunging part is on the end, the more water can be moved and pushed against the blockage. I got a new one recently for less than £4 that is about 7” across, and it is quite effective. The picture below shows a BOTTLE TRAP. These are used to prevent siphoning, when water flowing too fast can sometimes “pull” too much water out of the U-BEND. The downside is that they slow down the water flow, and can cause build up of soap scum in the waste pipe.

The product on the left (HARPIC POWER JET sink & plughole unblocker) was found to be very good at removing blockages in the trap and in the outlet pipe further down. It is very quick and effective. It is a one-time use pressurised container, with a liquid that is forced down the pipe. You need to have the overflow covered up with a wet cloth so that no pressure is lost whilst pushing down the can (the can is first inverted over the plug-hole, and an inch or so of water is run around it to provide a good seal). Follow the manufacturers instructions carefully, and ensure you correctly line up the two parts of the red top before use, as it is initially set in a position that avoids accidental release. It is sold in many supermarkets and hardware shops.