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10. Faults, causes and remedies
Only have faults remedied by qualified personnel!
Observe safety instructions in 9 Maintentance.
Fault
The pump does not start or stops
during operation
Pump does not switch on/off
Pump does not pump
Flow rate drops during operation
If the fault cannot be remedied, please
contact the trade or your nearest
Wilo-After-sales Service or agent.
18
Cause
Current supply interrupted
Motor protection switch has tripped
Fluid temperature too high
Pump silted up or blocked
Float switch blocked or cannot move
freely
Air in the installation cannot escape
Water level below the intake port
Pressure pipe / hose diameter too small
(losses too high)
Non-return valve sticking in the pres-
sure port
Hose kinked / check valve closed
Suction strainer blocked / impeller
blocked
Remedy
Check fuses, cables and electrical
connections
Allow the pump to cool down, it will start
again automatically
Allow to cool down
Disconnect the pump from the mains and
remove from the shaft.
Remove the suction strainer and rinse
the suction strainer / impeller under run-
ning water
Check float switch and ensure mobility
Place the pump at an angle in water
briefly until the air escapes.
Vent the installation / drain if necessary
Check the switch-off level
If possible, submerge the pump deeper
(observe the switch-off level)
Bigger dimensioning of the pressure pipe
/ hose diameters
check function
Clear kink in hose / open check valve
Disconnect the pump from the mains and
remove from the shaft.
Remove the suction strainer and rinse
the suction strainer / impeller under run-
ning water
WILO SE 09/2014