Installing a water softener: why and how?


When water is high in calcium and magnesium, it is said to be "hard". This is a natural characteristic of water and does not affect its drinkability. It can, however, scale your appliances and taps. To reduce the amount of limescale in your water, you can install a water softener.


Why install a water softener?

If your water is too hard, you can choose to install a water softener at home. You can check the hardness of your water on the page dedicated to the water quality in your municipality.  

See water quality in my municipality

You can limit the scaling of your pipes by keeping the temperature of your hot water below 60°C. Above this limit the scaling phenomenon accelerates considerably.

How does a water softener work?

There are several types of water softener. The most common and effective is the ion exchange resin softener. It removes calcium and magnesium ions and replaces them with sodium. Result: the water is softened. It is essential to maintain a residual level of hardness (15° French, 150 ppm CaCO3) to stop the water attacking the pipes. In particular, this could lead to corrosion. For this reason, it is not advisable to install a softener if you have lead pipes.


Note that water from an ion exchange resin softener has a higher sodium content. It could therefore be inadvisable for people on a low-salt diet, those with cardiovascular problems and for babies.


Regenerating your water softener

The use of a water softener requires regular and careful attention. For an optimal exchange between sodium and water, the resin should be regenerated approximately every 4 days.

How to take care of your water softener?

  • Install the softener on the hot water circuit. Scaling is promoted by the rise in temperature.  
  • Install the non-return valve in your system and check its operation. It avoids the return of softened water to the public network.  
  • Get a professional to install the softener. Before they leave, ask them to explain how the device works. 
  • Have your water softener serviced at least once a year. A faulty softener can cause sandy deposits in your system.

The installation of a water softener must meet the standards prescribed by Belgaqua, the Belgian water sector federation.

Belgaqua, Belgian water sector federation


Water softener tips

A useful brochure, including the do's and don'ts of installing a water softener.

See the brochure

More information about water softener can be found at