Getting your drains flowing again

A blocked drain usually shows itself on an ordinary day. The toilet is slow to flush, or the sink takes an age to empty.

The first step back to a drain that flows freely is working out who should clear it. In England and Wales the answer depends on where the pipe runs and how many homes use it.

Spotting a blockage

Thames Water lists three common signs. The toilet is hard to flush. The sink or bath empties very slowly. There is a bad smell coming from the drains.

When waste water cannot flow away, it can come back up through a toilet or sink and flood the home.

Working out where the problem is

Thames Water's guidance gives a few clues that a blockage is inside your own pipes.

The water company may be responsible if the problem is outside your boundary, or if more than one home is affected. If its engineer finds the blockage in a section that belongs to you, they will talk it through with you.

The pipes you look after

Homeowners are responsible for the drains, gullies and gutters inside their property boundary, as long as those pipes serve only their own home. If a blockage is in one of these pipes, the owner arranges for it to be cleared.

People who rent should contact their landlord or managing agent first. The landlord is usually responsible, though the tenancy agreement may say otherwise.

The pipes the water company looks after

Before 2011, many shared sewers and drains belonged to the owners of the homes they served. The government noted at the time that this usually came as a surprise to them.

On 1 October 2011 these private sewers and lateral drains passed to the water companies. A lateral drain serves one home but runs outside its boundary, for example across a neighbour's land. From the point where it leaves your land, the water company is responsible for it.

Any pipe shared with a neighbour also became a public sewer. That holds even where it runs under your garden or driveway. Water companies also own the public sewers under roads and footpaths.

Who to call

For a blockage in your own pipes, Thames Water suggests contacting a plumber or a drain clearing company. Some home insurance policies include drainage cover. For repeated blockages, or a drain you think is damaged, one council suggests talking to your buildings insurer.

For a blocked public sewer, contact your water company. Water UK has a postcode search that names your water and wastewater company. The local council deals with a blocked road drain, and GOV.UK can point you to the right one.

Keeping drains flowing

Sewers are built to take water from toilets, sinks, baths and showers, along with human waste and toilet paper. Thames Water asks people to put everything else in the bin.

Fat, oil and food scraps set solid in pipes. Wet wipes cause blockages, including ones labelled flushable. So do sanitary towels and tampons. Leftover cooking fat can be left to cool and then put in the bin.

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