Clogged sewer: what to do? Complete guide to solving the problem

Blocked drains can cause major inconveniences such as flooding and unpleasant odours. When a blockage forms deep in the pipes, or when natural and chemical methods are not effective, it's important to know what to do. This article guides you through the most effective solutions, including the use of a karcher and the intervention of professionals in complex cases.

Identifying the signs of a blocked sewer

Before you start, it's crucial to recognise the symptoms of a blocked sewer:

  • Slow flow : Water is difficult to drain from sinks, showers or toilets.
  • Gurgling : Strange noises are coming from the pipes.
  • Water rising : Water backs up into toilets, sinks or showers.
  • Unpleasant odours : Unpleasant odours emanate from the pipes.

Using a karcher with an unblocking hose

For blockages deep in the pipes, natural or chemical methods are generally ineffective due to the volume of water present. Using a karcher with an unblocking hose is often the best solution.

Preparation :

  • Make sure your karcher is fitted with a special unblocking hose.
  • Locate the manhole outside your drain to insert the pipe.


  • Insert the pipe into the manhole: Insert the unblocking pipe into the drain from the outside manhole.
  • Activate the karcher: Turn on the karcher. The hose will work its way to the plug.
  • High-pressure cleaning : The high pressure of the water will help to break up the blockage and clean the walls of the pipe.

Using a ferret

If you don't have a karcher, a less effective but useful alternative is to use a ferret. However, it is important to have a ferret that is rigid enough to be pushed into the sewer pipe, which is usually 100 mm in diameter. A sink ferret will be totally ineffective because it will roll up on itself at the first obstacle.

Preparation : 

  • Make sure you have a rigid ferret suited to the diameter of your pipes.


  • Insert the ferret into the drain: Insert the ferret into the drain from the manhole.
  • Turn the crank handle : Move the ferret forward by turning the crank handle to dislodge the blockage.
  • Remove the ferret: Once the blockage has been dislodged, remove the ferret and check the water flow.
  • Note: It is not advisable to use unblocking pipes, as they can often get stuck in the drain, aggravating the problem and making it more difficult for a professional to intervene.

When to call a professional

In some cases, using a karcher won't be enough, especially if the blockage is caused by roots or limescale. Professionals have more advanced tools for these situations.

Blockages caused by roots

Roots can penetrate and block pipes. A professional will use high-pressure tools and inspection cameras to locate and remove the roots.

Limestone slabs

Limescale deposits can harden and block pipes. A professional can use very high-pressure water jets to remove them effectively.

Why call in a professional?

  • Precise diagnosis : The experts can identify the exact cause of the blockage using inspection cameras.
  • Specialised equipment : Professionals use advanced equipment such as high-pressure jets and root cutters.
  • Effective intervention: They can quickly resolve even the most stubborn blockages, ensuring that your pipes work at optimum efficiency.

Preventing traffic jams

To prevent your drains from clogging up again, here are a few preventive tips:

  • Avoid throwing away grease: Grease can solidify and create blockages.
  • Use strainers: They prevent food residues and hair from entering the drains.
  • Do not use wipes: Wipes do not break down and can cling to limescale deposits or roots, forming plugs. Toilet paper, on the other hand, has a chance of dissolving and passing through more easily.
  • Maintain your pipes regularly: Use natural products such as bicarbonate of soda and vinegar for regular maintenance.

Determining whether the problem is private or public

It is very important to determine whether the blockage is a private or public problem. If the blockage is in a public sewer, you need to contact the local council.

How do you determine the nature of the problem?

  • Open your eyes: Inspect the manholes in your pipes to see if they are full.
  • Talk to your neighbours: Ask your neighbours if they are also experiencing traffic jams. If several houses are affected, it is likely that the problem is at street level.

Is your sewer blocked in the Hérault? Contact us!

A blocked sewer can be a source of stress, but with the right methods and tools, such as a karcher with an unblocking hose, you can often solve the problem yourself. For stubborn blockages caused by roots or limescale, it's best to call in a professional. The unblocking Experts are at your disposal (in the Hérault region) for fast, efficient interventions.


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