Wilo AF 22, Installation And Operating Instructions Manual, Page: 19 / 51

ENGLISH
13
7. Maintenance
The pump is almost maintenance free.
It is recommended that the unit be tested each year by Wilo customer
services.
If out of service for long periods, the drinking water inlet is to be shut
off, the mains plug removed and the pump/unit drained by opening
the lower pump drain valve (fig. 6).
8. Problems, Causes and Solutions
– Pump does not run.
– Voltage interrupted. Check fuses, connections and power supply.
– Pump switches off and shortly afterwards switches on again.
– Increase pump cut-in pressure in menu 2.13. The cut-out pressure
may not exceed the pump's zero delivery head (maximum pressure
of the pump at zero amount as per rating plate). If the cut-in and
cut-out cycles are too frequent the overshoot time can be increased
in menu 2.14.
– Pump capacity is too little or non-existent.
– There is air in the suction pipe. Seal suction pipe.
– Air in the pump. Ventilate the pump and the unit.
– Suction height has exceeded the maximum height or suction losses
are too great.
Check water level.
– Filter blocked. Clean foot valve.
– Pressure too low.
– Suction height too high. Check water level.
– Filter blocked. Clean foot valve.
– Pump leaky.
– Mechanical seal faulty. Replace mechanical seal.
– Tighten screws in stage housing.
– Drinking water backfeed active despite cistern being full.
– Level sensor dirty or faulty. Clean or replace sensor.
– Pump does not switch off.
– Check cut-out pressure and overshoot time. If necessary reduce
cut-out pressure in menu 2.13 and overshoot time in menu 2.14.
If the fault cannot be remedied, please contact Wilo customer
services.
29135_Wilo_RainAF22_GB 26.05.2000 8:23 Uhr Seite 13 (1,1)