Replacing a sink trap: a handy how to

If you're having problems with an old sink trap, such as constant overflows and stubborn smells, make a fresh start with a new trap kit. Here's a handy how to for replacing the old sink trap with the new.

• Container, (such as a bucket)
• Multi-grip pliers or wrench
• Plastic or metal sink trap kit
• Special trap adaptor (if required)

• The draining procedure is the same for metal and plastic sink traps.
• Remove the access plug if there is one, and drain all the water out of the trap into a container.
• Using multi-grip pliers or a wrench, if necessary, loosen the couplings.

• Take your old trap with you when buying a replacement kit.
• Standard pipe sizes have changed, and you may need a special adaptor to make sure your new trap fits.
• Lay out the necessary parts to see how they join together.

• Fit your compression washers, as shown in the kit instructions.
• Join the sections of pipe together and link them to your sink and floor wastes.
• Don't overtighten the fittings.
• Test the flow through any new pipes and traps first, and then gradually tighten to seal off any leaks.

• For blockages in your pipes that can't be cleared with a plunger, it's worth trying a device called a plumber's snake or spiral cleaner. You can buy or rent one. To use the snake, disconnect the blocked pipe from its trap and feed the end of the wire into the pipe. Then turn the handle to rotate the spiral. This drives the cutting head into the blockage and breaks it up.
• You can't dislodge a blockage in a U-bend with a plunger. Bail the water out of the sink, place a bucket under the U-bend, and unscrew the access plug with a wrench or multi-grip pliers. If water trickles out into the bucket, stick the end of a wire coathanger into the opening to snare the blockage and haul it out. If water gushes out in the bucket, the blockage is probably beyond the U-bend and it's time to call a plumber.
• Once you've cleared a blockage, replace any damaged components, such as rings that are worn or have been stretched out of shape. Correctly position your new sealing rings inside the screw-up fittings, otherwise the joints will leak. Applying a small amount of silicone lubricating grease to the sealing rings inside push-fit connectors to create a firm seal.

Keep these tips and handy how to in mind when you replace your sink's old trap and the job will flow that much more smoothly.