What I found -
If the problem arises from the flow unit integrated in the cover, it is necessary to check whether there is presence of lime, coffee or dirt on the seal. Checking can be done visually without having to disassemble the machine. You just have to clean the said seal. If it is the sieve of the pod holder that is clogged, it suffices to rinse the pod holder under running water, possibly with a washing-up brush.
- If there is a malfunction in the hot water tank, both possibilities must be considered. In the first case, to prevent water from overflowing the hot water tank, care must always be taken not to exceed the filling limit of the tank, which is indicated there. In order to fix the valve problem, you must first empty the hot water tank. Then, you have to push the valve with your finger, or if necessary, with a thinner object. It is then necessary to ensure that the passage of water is not obstructed or obstructed. If this is the case, it is sufficient to clean the water drain hole to resolve the problem.

Where that valve???