The fault you have described usually occurs when the non-return valve of the pump is either jammed by dirt particles, the filter at the pump base is clogged or the spring of the non-return valve is broken. To check and clean, please proceed as described below.
If the fault is still present after cleaning, an electronic fault must be assumed and the pump must be returned to us for repair. In this case, please send the pump with a brief description of the fault and proof of purchase to your local GARDENA Service.
Cleaning the non-return valve
Remove the 4 Phillips screws on the upper part of the housing
The connection adapter is fixed in place with 4 Phillips screws. After removal, the adapter can be taken off by pulling firmly.
The non-return valve can be removed and cleaned or replaced.
The seal and guide as well as the magnetic ring on the non-return valve should be cleaned.
The position of the pressure compensator for reassembly as shown in the photo.
Assembly is carried out in reverse order.