Kessel Aqualift S 100 Mono Instructions De Pose Et D'utilisation page 36

6.5 Backflow preventer
Open the backflow preventer carefully, allow the accumu-
lated water to flow out.
Open the turn fastener.
Remove the backflow preventer.
Clean the components in a water bath.
Ensure that the backflow preventer is movable.
Check tank for serious contamination, clean if necessary.
Sharp devices are not suitable.
Re-install the components.
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