It is much better to treat a sluggish waste outlet before it becomes entirely blocked and turns into an emergency. Scalding water is especially efficient against a build-up of grease, at a kitchen sink, but the blockage may also be caused by a small object which lodges itself across the pipe and other small particles of waste become trapped and quite rapidly build up into a fairly solid blockage. An ordinary rubber plunger and drain auger are the most effective tools to for freeing a blocked waste outlet in hand basins and sinks.
Clearing Pipes with a Plunger
Begin by plugging the overflow opening with soft cloth and allowing enough water in the basin to cover the plunger cup. Coat the rim of the cup with petroleum jelly and place in centrally over the plughole. Without breaking the seal between the sink and the cup, pump vigorously up and down. Then quickly release the plunger and this should free the blockage. If not, then use the drain auger or try cleaning the trap:
Clearing Pipes with an Auger
Should the plunger not work, then try the drain auger (snake), this is really an incredibly flexible metal coil that can be fed through the pipes until it reaches the blockage. The drain auger may be inserted into the basin if the strainer can be removed from the plug recess. Feed the auger into the waste by winding the handle clockwise. When you reach the blockage, move the auger backwards and forwards slowly even though still winding, and then slowly withdraw it, winding in the same direction.
Cleaning the Drain Trap
Most modern sinks and basins have a removable bottle trap that forms part of the U-bend and is situated directly below the plug outlet. Place a container beneath the U-bend to catch the water inside the trap. Unscrew the bottom half and probe (use a little piece of wood) inside and around the inner pipe where waste collects. Clean and replace the trap. Turn on the water to check that it is now free flowing.