How can I fix a wall-mounted toilet that keeps running?

Question

Our wall-mounted toilet keeps running. It is easy to "stop" by removing the plate with the push-buttons and pressing down the cylinder (valve?) inside, but I'd like to find an actual solution :)

It's hard-ish to find out what the issue is for me as I know nothing about these things, and it's inside the wall: hard to just take apart and look around.

The toilet is a 'Duravit', but I couldn't find any specs on the flushing mechanism itself, so this can be 'anything' I suppose.

Any idea how to fix it, or what I can check? Or just call a professional?

Now for some visual clarification:

First the button. When pressing it halfway it doesn't keep on running, but it's not a good flush like that. Pressing it all the way makes it stuck in 'open' or so it seems.

Inside of the button-set (seems like air-pressure makes it work?)

So this blue-topped cylinder keeps stuck in the 'up' position

About to press it down to make it stop flushing. An easy fix, but annoying obviously

Answer 1

We had a similar problem with our Duravit toilet. We followed the instructions above, and after pulling out both the intake water controller portion, as well as the flush control, he didn't find any calcium build-up: just some rust stains. As a final check, my husband reached down into the toilet tank and felt something stuck in the bottom stopper valve. He felt what he thought was a broken piece of rubber, and after tugging on it with some force, he pulled the foreign object out in his hand from the access hole in the wall, and found a perfectly intact, but dead scorpion]2 It must have died just that morning when the toilet started running. Luckily he wasn't stung.

Answer 2

There were 2 (or maybe 3) things I needed to know:

1. (easy) the fact that these things can be disassembled easily

2. (harder) how the flushing actually works

   and the third, the cause in this case:

3. calcium is evil

So after a friendly plumber who 'refused' to come by for such a trivial matter had proposed I'd take apart the thing, find something that was wrong, fix that, and assemble it first helped me get going, I removed a lot of parts:

1. front plate (see above)
2. Screws and the 2 platic rectangles keeping the front in place (see above)
3. The water 'hose' (iron thing, again, see above)
4. I removed the piece that starts/stops water flow with the floater (was on the left, no picuture) and gently set it down inside.
5. The plastic base was the trickiest to remove: one side had a mechanism, the other side neede to slide up (but needed some force). See picture below.

Now that we finally have some picture, this is what happens: The blue part on the big cilinder (also featured above) is the one that stops the flow of water, but the smaller (white) one is the one that pushes it up when you press the button (airpressure). That one was the one that didn't come down again, due to caclium buildup. Cleaning this fixed it! see picture of the problem before cleaning it.

Strange that a relalitvely new toilet (house is from 2008) will have this as a problem, so I suppose this will come back sometimes ;(

Answer 3

Duravit has used two different in wall carriers, Geberit, and Grohe. Yours is a Grohe. Both company have excellent technical customer support representatives that you can call.

That said, there are 2 things to check other than the obvious issues with worn flapper gasket. If it’s less than 5 years old, I doubt that’s an issue.

1. There is a diaphragm mechanism within the fill valve that will be easy to swap out when you have the replacement in hand.

2. The linkage “pins” or posts that contact the back of the actuator buttons need to be adjusted to the proper length, they telescope in or out then lock into place with slight torque.
   These are super easy to repair, for plumbing contractors that installed Duravit toilets.

You can get a really good parts breakdown from either groheamerica or visit geberit.usa. I believe it’s a Grohe. Their tech dept in Chicago is excellent

That said, these products are not “typical” DIY fixtures, and there is still high value with a contractor visit.

There are also decent YouTube videos to clearly illustrate how to get it done.