Flush-mounted cistern: Pros and cons of concealed flushing

Flush-mounted cistern: Pros and cons of concealed flushing

Until a few years ago it was more appropriate as exclusive, today the hidden toilet cistern is the norm. The flushing cistern in flush-mounted has long ago supplanted freestanding relatives in modern bathrooms. In more than every second household, the cistern is now hidden behind a wall installation. Because above all aesthetic reasons speak for the concealed cistern. But there are also drawbacks.

What is a concealed cistern?

Its hallmark is that it can not be seen. In a concealed cistern, the toilet flush hides in the wall of the toilet. Only the handle can be seen and operated from the outside. However, the term concealed cistern does not just mean the cistern itself, but the entire construction: the pre-wall installation and the flushing cistern built into it.

If you want to install a concealed cistern in your bathroom, you can choose between many different models. In most cases, these so-called toilet pre-wall elements made of steel and plastic and are not lightweight at an average of 15 kilograms. They can be installed at a height between 80 and 120 centimeters. The installation width is usually around 50 centimeters.

The different versions also offer various features. The client can choose between the following equipment elements:

  • Single flush
  • Dual flush
  • Upper actuation
  • Front actuation
  • Rinse hold yes or no
  • quiet models
  • self-supporting
  • Washbasins with adjustable Flush volume
  • insulated against condensation

The surface-mounted cistern is the counterpart of the concealed cistern. This is installed in front of the wall and visible. However, optical cladding is also possible here, which benefits the aesthetics.

The advantages and disadvantages of a flush-mounted cistern

Above all, a concealed cistern has an unbeatable advantage: you do not see it and hear it only a little. Due to the construction in the pretext the box is hidden and only the shutter protrudes from the wall. This especially supports a modern look of the bathroom. Foam mounting mats often provide sound insulation. In addition, the concealed cistern saves space - a big advantage, especially in small bathrooms.

However, the hidden technology also has disadvantages. So the installation and construction of the cistern is considerably more complex than with free-standing models in front of the wall. Also with a repair the do-it-yourselfer has to plan more time and work. However, today's sanitary technology is so advanced that cisterns can operate for more than ten years without any disruption. Dealers often give years of warranty.

Manufacturers, Prices and offers of concealed cisterns

The cistern in the pretext is due to the German family business Geberit. In 1964, he was developed by company leader Heinrich Gebert, who at that time was still traveling around Europe with the cistern under his arm, in order to promote the technology. But only in the 1990s, the pre-wall installation systems prevailed. Since then, the company has installed around 60 million concealed cisterns - the models in the "Duofix", "Kombifix", "Omega" and "Duofix" series are popular. and & quot; Sigma & quot ;. Other companies and manufacturers joined the trailblazer and also launched models for concealed cisterns on the market. The leaders in the segment today are therefore:

  • Geberit
  • Grohe
  • Villeroy & Boch
  • Aquamarine
  • Connex

Prices vary depending on the equipment and dimensions of the cistern. Simple models can be purchased from just 70 euros. Most toilet pretext elements cost between 80 and 150 euros. However, models with all the features and special features can cost up to $ 300 or $ 400.

The popularity of the hidden flushing systems is unbeaten today. At the Geberit factory in Pfullendorf, a packaged concealed cistern leaves the conveyor every four seconds. Here, about four million pieces are produced per year.

Installation of a concealed cistern

Anyone who wants to install a concealed cistern in their own bathroom should distinguish between two basic variants: wet construction or drywall. Here there are coordinated models in the trade. In most cases, the pre-wall elements of the WC are also preassembled.

The work on the supply line and pipes should be left to the skilled person. Similarly, the lifting of the surface for the cistern in the pretext is better in professional hands. The installation then takes place in several steps:

Aligning and measuring

The pre-assembled cistern element is inserted behind the rail of the opened front wall. Through different adjustment rails, the element can be varied in height as well as in depth. This allows the do-it-yourselfer to optimally adapt the cistern to the height of the water pipes - the holder for the drainpipe is particularly crucial here. Some cisterns also provide height markings that the craftsman can follow.

A balanced survey is a must. Do-it-yourselfers should not forget about the spirit level - and use it horizontally as well as vertically to optimally adjust the installation.

Drill holes and dowels

After the cistern is aligned, the do-it-yourself can drill the holes for all wall connections Mark installation. These are usually six pieces: on the floor and on the wall. Then the construction is lifted out again and the holes are drilled in the wall with the machine. Dowels are sunk in.


Only now should the drain pipe of the WC flushing be inserted into the drain. When re-fitting the pre-wall installation, the support for this pipe can now be opened at the bottom to fit into the installation. When inserting the WC element, the tube must engage in the holder. Then the construction can be attached to the drilled holes with screws to the wall. Finally, the tradesman must also use the inlet valve, inlet hose and front panel and screw in the threaded screws for the WC body.


This completes the actual installation. The front of the concealed cistern is then closed. Here there is the variant of wet construction, which offers a masonry paneling. The expert uses here mostly Gastbeton- or aerated concrete blocks. The drywall cladding is often made of fiberglass-reinforced drywall panels, as they better support the weight of tiles attached to them.

If something is broken: open and clean the concealed cistern

Although WC wall-mounted elements have a long service life, they do sometimes work still a bit broken. At the latest when the toilet lavage licks, the concealed cistern should be opened and maintained. In some cases, limescale cleaning and liberating is enough to make the system work properly again.

To open the under sink, the actuator plate can be pushed up slightly. This will solve them and the handyman can now easily remove them. Often a cover comes to light. This can be removed with two screws. This will often expose access to the cistern - in some models, there are also intermediate steps.

Next you should turn off the water inlet at the angle valve before you can replace the individual parts such as filling valve or bell spring. Here you can easily find the right replacement parts, because the manufacturers still keep those for the models from the year 1964.

Close the toilet lid when opening the cistern. So no screw can accidentally fall into the water.


A concealed cistern is installed in the pretext. Usually this is not only the cistern itself, but the entire wall element with scaffolding, adjustable rails and Co. manufacturers offer different variations, which differ in features and price. The installation can be carried out by the skilled person as well as the skilled craftsman himself.

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