Where do I find the check valve?

The check valve prevents the water from being sucked in through the suction hose of the pump filter and then expelled again through the suction hose. Instead, it allows the water to be sucked in and then conveyed towards the filter element. Sediment, lime scale and other particles can cause the check valve to stop working properly. In this case, water is usually no longer sucked in or is pumped back. Here you will find the check valves of our pump filters and how to remedy a blockage:


Two metal balls form the heart of the check valve. They can be loosened by gentle shaking. Lime deposits can be dissolved and removed with a few drops of vinegar or citric acid. Then rinse thoroughly.

Katadyn Pocket

The check valve comes in the form of a white membrane. The movement can be observed through the housing during pumping (even without filter element). To loosen, swing out the housing without the filter element in a bucket of clean drinking water or rinse with clean tap water.

Katadyn Hiker

The check valve on the Vario appears in the form of the large, round umbrella valves on both sides of the head section (here 1x left and 1x right). Much more often, however, the overpressure valve has a blockage, which is shown by a spring-loaded plastic ball on the edge of the housing. To loosen deposits, use a blunt, rounded object to gently rotate the ball. To rinse and check the screen valves, fill the head section with water with the opening facing upwards and pump several times, then completely reassemble the Vario and check again.

Katadyn Vario

The check valve is shown in the form of two obstructed balls.

Unscrew the ceramic element and fill it with clean water to rinse off sediment and other deposits. Repeat the procedure from the other side.

Caution: Nothing can & must be removed manually at this point, otherwise the filter housing will be damaged.

Katadyn Combi