If at any of you sometimes only water overflows when bubbling and no more carbon dioxide goes in, simply try the following:
At the injection part of the device above the lid open (not the injection button). Since there are two high plastic parts. The rights of these is the pressure relief valve, the other is to release pressure when opening the device. These valves are adjustable by a thread and therefore loosening over time and fall apart.
Positives:
Almost all parts are made of plastic, but which is very stable and resistant and makes a good impression.
The device looks good, the carbon dioxide can be quite well dosed. There are no parts that need to be absolutely clean, except the bottle of course.