Replace the cistern from the toilet


The toilet is in use every day. Thus, the sanitary device also experiences a high degree of wear. Consequently, it is always necessary to replace the cistern with a new one. Below you will find instructions that you can use to replace the cistern on your toilet yourself.

The toilet cistern must be renewed again and again

The toilet is so natural that we usually do not even consciously perceive how it is set up at all. But the daily use of the mechanism inside the cistern exposes it to significant wear. There are many reasons for replacing the toilet cistern:

  • so calcified that descaling would be extremely expensive
  • Defect on the mechanics inside
  • optical defects on the cistern
  • Cistern is no longer tight
  • Cistern does not have a savings button yet

Avoid replacing the cistern

Of course, in most cases you should first try to descale or clean the toilet cistern. If the toilet cistern leaking, there are also ways to repair the toilet cistern. However, if the cistern has mechanical or optical damage or just no economy button, the repair is not worthwhile.

The different toilet cistern systems

There are no differences in the connections. They are standardized and the same for new toilets. However, there are significant differences in the cistern systems:

  • Toilet cistern mounted on the toilet ceramic
  • Toilet cistern hanging on the wall (in conventional height or hanging high)
  • inside cistern behind toilet wall

The mechanism is always supplied with the cistern, as well as in most cases the mounting material. However, if you want to replace the cistern in an old building, often still lacks the angle valve, so the faucet especially for the toilet. Instead, the main water tap for the whole building must often be turned off when needed. In an apartment building, it would then make sense to install such an angle valve with the same.

Step-by-step instructions for replacing a cistern with the toilet

  • cistern
  • possibly new pipe connections (eg downpipes in high-hanging boxes in old buildings)
  • Hemp for sealing pipe connections with threads
  • possibly rust remover
  • Lime and urine stone solvents (commercial cleaners, corresponding acids, etc.)
  • Soundproofing plate for wall installation cistern
  • wrench
  • screwdriver
  • Wasserpumpenzange
  • ratcheting box
  • possibly fine-toothed saw (for cutting the tubes)
  • Lubricant (so that pipes slide better together)
  • spirit level
  • Meterstab
  • possibly drill with appropriate drills (porcelain stoneware, glass, natural stone, etc.)
  • soft wire brush (copper or other light alloy)
  • rubber gloves

1. Remove the old cistern

In the past, metal threaded rods were often used to attach cisterns to the toilet. But these are regularly splashed with water and urine. Therefore, these metal threaded rods can be badly corroded. In this case, it is recommended to spray the threads vigorously with rust remover on the eve of replacement.

Then turn off the water, empty the cistern and disconnect the water inlet connection in front of the cistern. The inflow pipe from the cistern to the toilet ceramic is often tightened on the toilet side with a screw-down rosette. They solve this. You can now lift attached cisterns simply upwards. For cisterns that hang on the wall, it makes sense for a helper to hold the cistern before loosening the fixing screws.

2. Clean everything before replacing

If you do not want to replace the toilet ceramics, you should clean them well before putting on the new water cistern. You can proceed as we have summarized it under toilet descaling for you.

Now you have to clean the water connections for the Spülkastenzulauf. For metal threads, use a small wire brush (something the size of a toothbrush). If limescale deposits are found here, you can also use limescale cleaner here - provided the cleaner is suitable for the existing metal!

3. Fit the new cistern

The cistern mechanics have different systems. Before installing the flushing cistern, check whether, in particular, it is necessary to screw on the cistern drain from below if it is a box placed on the toilet. In this case, you must now assemble everything according to the installation instructions.

Prepare the connection material (today these are usually plastic threaded rods). When placed on the toilet cisterns comes between cistern and toilet ceramic a rubber washer. The installation instructions of the flushing cistern manufacturer should give you precise information about this. For hanging cisterns, you can mount a soundproofing panel between the wall and cistern.

Now grease the feed well with the lubricant. The external thread between cistern and angle valve wrap around with hemp. Now carefully put the cistern on. If the cistern is placed on the toilet, do not fully tighten the screws. The cistern should still be moved.

Now tighten the rosette on the ceramic inlet. Then connect the water inlet in front of the cistern. It may still be necessary to install an angle valve (if there was none).

4. Mount the mechanics of the cistern

If you can only use the cistern mechanism now, proceed as the manufacturer described in his manual.

5. Theses

Now align your cistern (top cistern) and tighten it firmly. Then turn on the water and check everything for leaks.

Tips & Tricks

If you also want to replace the toilet seat glasses, we offer here the appropriate installation instructions: Mount the toilet lid.


Video Board: Fix Constantly Running Dual Flush Toilet Cistern By Replacing The Flush Valve Washer