[Solved] ROCA Concealed Cistern Low Pressure Issue: How to Increase Flush Button Pressure?

Ladies and gentlemen,

Hello to all users of the website. I have a problem with a concealed cistern. It is a ROCA cistern (I did not choose the mechanism - the cistern is probably about 12 years old)

When I press the button, the flush, instead of draining all the water, only drains a little (5% -10%) of the entire tank volume.
Only when I press the button quickly about 10 times, water is able to rinse the entire shell.

I wanted to ask if someone polite would advise on how I can increase the pressure at the push of a button. For now what I have done is:
I took off the cover,
I took off and cut off the ends of the two plastic tubes (in the video) that drain the pressure into the tank,
I put them back on.

Thanks to this, I ruled out that the air was escaping through the gap between the tube and the connection with the button. Unfortunately, the cistern still has low pressure.

I am asking you for help in this matter.
Best regards and thank you for your interest in the subject

The cistern works by gravity. First of all, all items need to be cleaned. Then a visual inspection and troubleshooting. Or the entire mechanism to be replaced immediately (should not be expensive) if available.

Zbych034 wrote:

The cistern works by gravity. First of all, all items need to be cleaned. Then a visual inspection and troubleshooting. Or the entire mechanism to be replaced immediately (should not be expensive) if available.

Dear Zbych. Thanks for the hint. I was able to determine that the button mechanism is GROHE67205 and it can be unscrewed to get to the flushing mechanism. Pictures below




Nevertheless, I have no experience in this - do you know where I can find instructions for such cleaning of the flushing mechanism or preferably instructional videos. I couldn't find anything on youtube.

Greetings!

Hello,

JuhasSas wrote:

This is a ROCA cistern

JuhasSas wrote:

that the button mechanism is GROHE67205

Is it Grohe or Roca? :)

The mechanism inside the tank is different and the button is different?


The very cleaning of everything is simple, it can be more complicated to remove the mechanism from the inside, also I did not find any instructions - hmm, but I was looking for the Grohe mechanism, maybe Roca will find something.

Have you read here?
https://www.elektroda.pl/rtvforum/topic3241068.html

Parowy wrote:

Hello,

Hello :)

Parowy wrote:

Is it Grohe or Roca?
The mechanism inside the tank is different and the button is different?

I had a ROCA shell and assumed before that everything was from the same company. Misconception - Sorry for the confusion.

The button is definitely GROHE. And there are many indications that the mechanism is also. The inside looks similar to the one in the movie: https://www.youtube.com/watch?v=wZgrOEvBTvw

Parowy wrote:

The very cleaning of everything is simple, it can be more complicated to remove the mechanism from the inside, also I did not find any instructions - hmm, but I was looking for the Grohe mechanism, maybe Roca will find something.

Unfortunately, I still do not know how to remove the entire mechanism.

Parowy wrote:

Have you read here?
https://www.elektroda.pl/rtvforum/topic3241068.html

Yes, but unfortunately there is no information about too low pressure and disassembly of the tank.

Additionally, I have a hypothesis that maybe the button is broken. When I press it, the blue element (in the video) rises (and some of the water falls) but then it quickly drops (the water stops flowing. The second time the same. Only the third time when there is less water in the tank, the pressure from the button raises the blue one element and rinses the entire shell.

Two videos here:
https://youtu.be/LcUALSY7xvw
https://youtu.be/OOShbYxMEPM

My question is:
According to your experience, is it not the fault of the button that generates too little pressure to lift the blue element?

I am asking for help and best regards

It is very possible, but you cannot eliminate leaks or jams without thoroughly cleaning the whole mechanism, so the amount of rust and scale does not bode well for you.
I myself had a similar problem with geberit - flashlight and combine, the stone blocked the valve lifting.
In the end, I was able to disassemble and clean, and temporarily rescued myself with boiling water with kamix - it helped for a while.

I provided a link in response to your question about interior cleaning (sorry, I didn't quote for the sake of clarity), this should be the first thing to do.

All the guts of the cistern are disassembled through the button hole, some just come out, others have to be unfastened (a hook, latch, etc.), and still others rotate by e.g. 90 degrees.

It will be hard to come up with something until there is better visibility inside :)


Edit:
Judging by this photo,



looks like something needs to be turned here.

Hi.
Most of the bells are push-fit, secured at the height of the window with either a latch or a crossbar, sometimes you can hit a flush with catches, just turn it a little and pull it out.
From experience, such cleaning often does not give much, because the scale does a lot of damage to the mechanisms and seals. Pitting and porosity are formed, that all this will not slip as much as new. You'll get a break, you'll get it, and in a week's time, the same. I would advise you to buy a replacement, because after 12 years I do not know if you will get the same system.

You may find it useful:
https://www.schneordesign.com/diy/diy-misc/grohe-gd2-fix/

I have Geberit and I used vinegar to descale it 18 years later.
I drained the water, poured a bottle of Lidl vinegar into the tank, waited about two hours and drained the water, then repeated the operation. Most of the stone had drained and the mechanism could be dismantled.

Hello
I have a very similar problem. For me, in order for the water to run, you need to press the button strongly and hold it for 10 seconds. A simple press has no effect.
I undressed and cleaned the water pouring element (because it was easy to disassemble). Flushing element - I do not know how to choose it. I don't know where the two hoses are going. Maybe they give too little pressure or what?
Anyone have any idea?

[movie: c043f16121] https://filmy.elektroda.pl/31_1563952663.mp4 [/ movie: c043f16121]

I solved the topic by ordering a specialist. It turned out to be a very non-standard flush model and only the second specialist dealt with it.

Thanks for all the tips!