There is no need to replace older exposed cisterns just because an inlet or outlet valve is defective. After all, there are appropriate Geberit inlet and outlet valve systems not only for every older Geberit concealed cistern manufactured since 1964, but also for exposed or other cisterns from numerous manufacturers.
For every older Geberit concealed cistern manufactured since 1964, there is a suitable conversion set for converting from a single flush to a stop-and-go flush or dual flush (1978 and newer).