Clearing Wastepipes

Water draining slowly from a sink, bath or basin is a sure sign that a serious blockage is imminent. Leave the water to drain, then pour a chemical cleaner down the waste outlet to dissolve the obstruction before it becomes a major problem. Flush out the waste system with clean water.

If a chemical cleaner fails to clear the blockage, try using a sink plunger. Ensure there is enough water in the sink to cover the rubber cup of the plunger. Block the overflow outlet at the back of the sink or basin with a wet cloth. Place the plunger over the waste outlet and pump the plunger up and down to create pressure in the pipework.

Alternatively, use a hand-operated hydraulic pump. Fill the pump with water and place it over the waste outlet. Push down on the handle to force a jet of water through the wastepipe.
If you cannot shift the obstruction with pressure, you will have to dismantle the waste system. Sinks and basins are fitted with water-sealed traps, designed to prevent drain odours entering the house. Check the trap for a blockage.

A bottle trap is designed with a large access cap. Place a bucket under the trap and unscrew the cap. Wash out the trap then refit the cap.

To clean a trap that forms a U-bend, you will have to remove the complete unit unless it is fitted with a cleaning eye sealed with an access cap. Access may be provided for clearing blockages in the waste pipe beyond the trap. If not, remove the trap and pass a hooked wire into the pipe to free the blockage. Alternatively, buy a flexible drain auger.

For more DIY Plumbing advice, visit www.diy-extra.co.uk