Kessel Ecolift XL Installation And Operating Instructions Manual page 37

Backflow preventer maintenance
Close both shut-off valves.
Vent the backflow preventer. If no flowing noises occur after venting, maintenance work must be carried out on the back-
flow preventer. Carry out the maintenance of the backflow preventer as follows.
Undo the hexagon screws on the flange.
Open the one-handed closure.
Remove the backflow preventer.
Remove blockages and/or blocking objects.
Clean the backflow preventer in the water bath.
The shut-off valve must be replaced if one of the shut-off valves is difficult to close or open, even after multiple operation.
Sensor system maintenance
Dismantle and clean the immersion pipe and pressure
hose or level sensor if necessary.
Dismantle and clean the optical probes (including redun-
dant sensors if applicable).
Check the function of all optical probes and, if installed,
the level sensor.
Re-install the sensors.
Complete the maintenance
The maintenance is finished if the functional check has been carried out successfully and no error messages are dis-
played at the control unit.
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