Geberit Valve Type 330: Water Overflow Issues and Impact of Low Water Pressure

Hello,

I have a problem in the toilet with this valve, which after filling the tank and lifting the float does not cut off the water supply (water overflows into the shell). The frame with the valve is new and never used (unfortunately after the warranty). I took the whole valve apart and put it back together and nothing has changed. Manually lifting the float up to the maximum also does not cut off the water supply.
Could this be affected by low water pressure? Is any minimum house water pressure required for proper water shutoff?
I would be grateful for any advice.

Hello

paawelx wrote:

Manually lifting the float up to the maximum also does not cut off the water supply

And is there an end that cuts off the water supply under pressure from the arm? And if it is, does it move at all or is it standing rigidly?

It is exactly like the picture. This blue tip also moves when the float is raised. At the end it has a small rubber band that clogs the hole, but even when you press it down more, the water continues to pour.

Replace the whole thing. If you look for it well, you can buy a new copy for even PLN 20 from a customer who bought it by mistake or if something does not suit him and wants to get rid of the part.
greetings

I changed the valve from another, free set and it works. I am not closing the topic yet, because I will try to fix it. Can anyone know the principle of operation or can explain why such a new valve does not cut off the water?

paawelx wrote:

Can anyone know the principle of operation or can explain why such a new valve does not cut off the water?

Usually this is where the cause is

As far as I remember correctly, replacing the gasket solves the problem.

I understand that this gasket is not universal. Where can you buy it (except for the entire valve, of course)?

paawelx wrote:

Where can you buy it (except for the entire valve, of course)?

Take the pattern out and you will get it at any accessory store. E.g. Castorama etc.

I dismantled the whole measure, what is marked in the picture, I blew it, it works and it works. And I also struggled with this float and rubber band

Maybe I`ll add it and it will be useful to someone. My analysis shows that water enters through the cuts in this plastic mounted on the membrane. The hinge presses against the rubber band, so the water can no longer drip (it`s supposed to drip), and the pressure equalizes by pressing the membrane against this round plastic circle. As the hinge falls, the ambient pressure is lower, and again the force of the water pushes the membrane away and water pours out. Generally, in my case there was a small sprue at the water outlet from this mechanism, and the plastic cover rested on it, which caused a pressure drop under the diaphragm. It was fine before, but over time the membrane formed but was not pressed evenly. Either way, clean it, check the surface, and if it doesn`t stick, replace it. This is a very precise system, and if the diaphragm is stiff or has a rubber band in the hinge (the black one), it becomes stiff, this means a pressure loss and the shut-off will not work. I hope that my 3 hours of analysis will be useful to someone, it won`t be wasted.

I feel that it is further not explained exactly why the water in the "float" does not fly. Regardless of the type and model, Geberit used the same method to cut off the water in the float. This movable part, which rises when the tank is filled with water, has this red soft rubber stopper (visible when the vertical arm that rises is removed). This very rubber band opens and closes the tiny air hole that goes into the chamber where the water flows in. And it is this very tinyness of the hole, or more precisely the clogging of it with stone, that causes the water, having no air outlet through this hole, to simply not fly through the float. No gaskets etc. are to blame (even the float construction video on YT does not show this hole). I.e. there could be various causes, but this through-hole is strategic - it could also be from new as if clogged with an uncut piece of 'plastic'. It took me two days to figure out what was cutting off the water in the float, as there is no horizontally moving part with a gasket that closes and opens the water supply. Well, apart from the aforementioned one.

I think we are both right. I have also focused more significantly on this hole and it is as you write, and it must be unobstructed. However, it seems to me that at the beginning there may be air coming out of it, but once this whole chamber around this hole is filled with water, then water must flow out of it, because water should either drip or ooze, or even flow, depending on the design and size of the hole in question. And then there is flow and there is filling. If you tighten this hole and block the exit of this water, the whole valve closes. From my analysis, this design is due to the lower force needed to close the water yesterday, because you really only have to cut the flow out of that hole and you don't have to push the whole mechanism into the pressure that is in the pipes, and it has quite a force. We know this because when the gasket in the tap goes down, the water squeezes through forcefully, and here with a delicate plastic float that doesn't generate too much force and isn't supposed to stress the components, but only control the flow. You can compare it to an electrical relay, it doesn't take power but only controls the contact. Anyway, I agree with the previous speaker that this hole is very important and I hope that someone will find our advice useful.