Drain Valve Removal for Cersanit Aqua Concealed Cistern: Step-by-Step Guide & Tips

Hello, I want to remove the drain valve from Cersanit Aqua concealed cistern. The instructions are very skimpy "catch from the bottom and pull out", unfortunately, but you have to unlock something else.

Thanks for the help.

Added after 3 [hours] 5 [minutes]:

I already know, should just pull up very much, there is a groove on one of the sides, when putting in, pay attention to it, I have replaced the gasket and no more water is pouring. The gasket is a cost of PLN 22 per piece of rubber, a rip off

You answered it yourself, and if it is too expensive, you can take a piece of rubber and cut it yourself