This instructable is about fixing a specific symptom (described below) on a Geberit in-wall toilet flush with two separate buttons for flushing with a smaller or larger amount of water. The specific flush in use has a bell with part number 240.622.00.1.
I hope that the instructions provided, here, may also apply to other similar parts from the same or other manufacturers. However, please apply common maker sense, before trying them. Also please understand that I will probably be unable to answer any questions on any other make of toilet flush.
- You have a Geberit in-wall toilet flush with separate buttons for flushing with a small or a large amount of water.
- Eventually, the button for the small amount of water stops working, while the button for the large amount of water continues to work.
- The "small" button may initially work some of the time.
- It may also "get stuck" some of the time, resulting in an unstopping flush.
One or both of two small latches on the bell have broken. We'll replace them using some very simple 3D-printed (or handcrafted) parts. No need to replace the entire bell.
Step 1: Remove the Outer Cover
To remove the outer cover gently push upwards from below, then tilt the upper edge away from the wall.
Your make of cover may differ, and possibly so does the fixation mechanism. Try pushing and prying gently, from all sides.
Step 2: Remove the Outer Frame
Pull out the blue fixation latches (one up, one down). Turn the white plastic bolts inwards, then pull them out. Remove the frame. The second picture shows the right bolt losened, while the left one is still in place.
Step 3: Take of the Inner Lid
This is easy, really. Remove the white lid.
Step 4: Remove Mounting Bracket
Remove the mounting bracket by pressing on the latch, and pulling upwards, gently.
Step 5: Extract the Bell
- Turn off the water supply (if you haven't, already). In my case, there is a convenient valve (top left, blue) for this purpose inside the tank.
- Extract the bell from the tank. It is fixed on the backside using a gray holder, which you will have to take off, first. The biggest obstactle will be getting it out of the access hole, with the limited space you have. Try various angles, eventually, you will succeed. (Somehow it got in, after all, so it can also get out).
Step 6: Find the Fault
Pushing the "large" button lifts the central cylinder, while pushing the "small" button lifts an assembly mounted around that cylinder. The catch is that this outer assembly is suppose to also raise the inner cylinder, but a only by a little bit.
Note the small rim on the inner cylinder (if you cannot see, what I'm talking about, click on the image, and mouse over to see annotations)? This is where the the inner cylinder is supposed to be lifted. Note the small latch that does the lifting? No? Well, that's because it is gone. A second latch is supposed to be present on the other side. It's probably broken, as well.
Please note that the small rusty hole (barely visible on the image) is not a part of the bell. It's a leftover from a previous, unsuccessful attempt at fixing the problem.
Step 7: Add Replacements for the Broken Latches
The latches are not too difficult to replace, and perhaps you'll have your own solution in a matter of minutes. However, when designing your own fix, be warned that the rim on the inner cylinder must stay above the top of the outer assembly. Having is sink in even a few millimeters may result in an non-stop flush.
Below, you'll find two different STL models, and a freecad file for the replacement latches I used. These are simply slid onto the pastic from above.
The first variant of the 3D model has small notches. These cramp into the holes that I had already drilled into the white plastic on each side, in an earlier unsuccessful attempt to fix teh problem. These notches will hold the repair pieces in place really tight. If you prefer not to drill any holes, use the other variant of the STL, instead, and the latches will probably still hold.
If you don't have access to a 3D printer, consider just filing / sawing something out of a small bit of plastic, referring to the pictures above. Or feel free to email me, and I can send you a pair of latches for a small donation and postage.
Step 8: Reassemble and Flush
Re-assembling your toilet flush is simply the reverse of the disassembly. Make sure to turn on the water, again, before closing everything, and I hope your flush is working flawlessly again, now.
If this instructable has helped to save you time and money, consider sending me a small donation via paypal: email@example.com . Thanks!