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Pipe under the washbasin

Why is the siphon actually curved?

Siphon
The trap is the curved part of the drain pipe under the washbasin or sink. Photo: Getty Images

October 10, 2024, 10:39 am | Read time: 2 minutes

The siphon – the pipe under the washbasin – has a very specific shape and two important functions. What are they? And how do you clean the siphon properly?

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It’s hard to imagine today, but European cities in the 17th and 18th centuries must have stunk terribly. Alexander Cumming faced this problem. Born in England at the beginning of the 18th century, the clockmaker set himself the task of putting a stop to the stench. His water closet, developed in 1775, already described a curved pipe that was supposed to keep the smell out. This brings us to the first fundamental function of the siphon.

What is the siphon’s function?

The siphon serves as an odor trap and is designed to prevent sewer gases from entering the home through the drain. This is why the siphon is usually designed in its typical S-shape. This is because the part below the drain hole in the wall is the lowest point and is always filled with water, keeping gases out.

The second function is probably not deliberate but is nonetheless very important. If something should ever disappear down the drain, such as a ring or a tooth, it is highly likely that the object can be found in the siphon. Provided, of course, that you haven’t let too much water run through afterward.

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Drain stinks – how do you clean the trap?

One reason why your drain still stinks could be that the water has been standing for too long or that it has already run out. In both cases, it is advisable to add water. Another could be that soap residue and hair have combined to form a mass that no longer drains. If the stench does not disappear, you should definitely clean the siphon. Here’s how to do it:

  1. Turn off the water supply in the room in question. The taps for this are usually located nearby.
  2. Place a bucket under the siphon so that the water can drain away.
  3. Now, carefully unscrew the plugs on both sides using a pipe wrench. It is best to unscrew both sides almost completely so that you can hold the siphon with one hand for the last part. If you place a towel between the pipe wrench, you will also avoid scratching the screw rings.
  4. Pour the contents of the siphon into the bucket and then clean it thoroughly.
  5. Now screw both sides back together.
  6. Turn the water supply back on and allow water to run through slowly.
  7. If everything is tight, you can open the taps again as before.

This article is a machine translation of the original German version of MYHOMEBOOK and has been reviewed for accuracy and quality by a native speaker. For feedback, please contact us at info@petbook.de.

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