Cistern Replacement Parts - What's Available and When's the Repair Worth It?

Cistern Replacement Parts - What's Available and When's the Repair Worth It?

With a bad flush Sooner or later, most people will have to do something in their lives. Such a defect manifests itself, for example, in that the rinsing pressure decreases, water constantly runs into the toilet bowl or the cistern is no longer completely filled with water. In principle, it is no problem to repair a broken toilet cistern. All you need is suitable spare parts and the corresponding know-how for the repair. However, once you have opened the cistern, you will be amazed at how much technology it contains. Many hobbyists are then afraid to do something wrong and destroy the toilet flush irreparably. For this reason, we explain in this guide the most important components of the cistern and explain what to look out for when you want to buy replacement parts. In addition, we address the question of when a repair may no longer make sense.

The possible toilet systems at a glance

Before we come to the actual construction of a toilet flush, we present below the various toilet systems that are in Germany are common. Although the following systems all work according to the same principle, they differ in their structure and method of attachment:

  • Toilet with cistern mounted on the ceramics of the WC
  • Toilet with wall-hung toilet box
  • Toilet with high-mounted cistern (directly below the ceiling)
  • WC with pre-wall element - as surface-mounted or concealed version
  • Toilet with pressure flush

Almost all toilets have a cistern.

What does the cistern look like from the inside?

Inside each cistern, you will find similar components inside, because the functionality of each cistern hardly varies. First, you will discover a bell tower with overflow. It looks like a tubular drain plug and is open at the top to ensure overflow. In addition, the actuating mechanism is located in cisterns. It consists of the individual actuator plates, which are connected to the Heberglocke. In addition, you will find in the cistern a filling valve (float valve) or inlet valve. It is columnar-like and has the so-called float bell. The inlet to the cistern is also provided with an angle valve and the flexible hose, while the drain consists of a flushing pipe.

Older toilet flushes may be missing the unit consisting of float and inlet valve. Instead, you will discover a hard foam body here. A lever serves as a connection to the filling valve.

In addition, the individual cisterns differ in terms of the mechanisms required to operate the flush: in the case of an on-wall installation, there is a pusher plate. Behind it is the module frame on which the actuator module is mounted. In conventional cisterns, the flush is actuated either by side buttons, push buttons or handles that can be pulled up. However, the actuation mechanism is very robust in almost all cisterns, so that only rarely something breaks. Many brands also offer complete kits for cistern operation. Therefore, in this case it is no problem to repair the toilet flush.

In addition, there are still modern cisterns, where the inlet valve is a special feature: Here there is not just a float that looks like a bell. Right next to it is still the plastic threaded rod. It is rotatable and can be used to adjust the float. In this way, you have the option of determining at which level the inlet valve should shut off the water inlet.

Which parts of cisterns are often broken?

When the cistern is broken, you will usually notice that the water is flowing continuously into the toilet bowl, the flush does not build up adequate pressure or the cistern is no longer completely filled with water. In this case, the following parts of the cistern are usually affected:

  • Seals on the inlet valve below the float
  • Float
  • Activation arm from the float to the inlet valve
  • Flexible hose
  • Inlet valve

If the cistern is leaking, This is mostly due to the fact that the seals on the inlet valve or on the drain are calcified or even porous. Rarely is the actual filling valve broken. But that can happen too. Likewise, the float sometimes does not work properly anymore.

A flush that constantly runs aground with water is not only annoying, it can also drain your money because over time, large amounts of water are wasted.

Everything in So, all you have to do is open the cistern and check for porous, calcified or broken parts and replace them with the appropriate parts if necessary.

What to look for when buying spare parts for the cistern

As soon as You know which spare parts you need to buy, you can get them either in a hardware store or directly online. In any case, make sure that the spare parts are compatible with your cistern. In principle it is recommended to buy the accessories according to the brand of your cistern. There are spare parts from all famous brands such as Geberit, Viega, Sanit, Wisa, Schwab and Grohe. Partially also universal accessories are offered.

If you ever buy spare parts for toilet flushing, you can consider directly upgrading the cistern. For example, you can buy a conversion kit for an automatic stop function.

There are also many spare parts in a handy set that can save you money compared to buying them separately.

Is the repair really worth it?

At For flush-mounted plumbing, repairing the cistern interior is often the only way for hobbyists to repair the toilet flush. If you wanted to renew the entire cistern in such constructions, the entire wall would have to be opened. This is a huge effort because the tiles have to be knocked off and the cladding has to be loosened. Therefore it is advisable in this case to buy the corresponding spare parts and to repair the conditioner.

The situation is different for surface-mounted cisterns. Modern designs are relatively inexpensive depending on the manufacturer and model. They often work water-saving and are more comfortable than old cistern models. In addition, the spare parts for very old cisterns are usually very difficult to obtain and can also be very expensive. In such situations, therefore, it is often better to replace the cistern with a modern one.


If the cistern is leaking and running water or flushing does not produce enough water pressure, you can buy replacement parts. to fix the defect. They are offered for all major brands. Only very old cistern models should be considered for the replacement of the complete cistern.

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