Grundfos CM-L Montage- Und Betriebsanleitung Seite 13

Fault
6. The pump performance is
unstable.
7. The pump runs, but gives
no water.
8. The pump runs backwards
when switched off.
9. The pump runs with
reduced performance.
Cause
a) Pump inlet pressure is too
low.
b) Inlet pipe is partly blocked by
impurities.
c) Leakage in the inlet pipe.
d) Air in the inlet pipe or pump.
a) Pump inlet pressure is too
low.
b) The inlet pipe is partly clogged
by impurities.
c) The foot or non-return valve is
stuck in its closed position.
d) Leakage in the inlet pipe.
e) Air in the inlet pipe or pump.
a) Leakage in the inlet pipe.
b) The foot or non-return valve is
defective.
c) The foot valve is stuck in
completely or partly open
position.
a) Wrong direction of rotation.
b) See 6. a, b, c, d.
Remedy
Check the inlet conditions of the
pump.
Remove and clean the inlet pipe.
Remove and repair the inlet pipe.
Vent the inlet pipe or pump.
Check the inlet conditions of the
pump.
See 6. a.
See 6. b.
Remove and clean, repair or replace
the valve.
See 6. c.
See 6. d.
See 6. c.
See 7. c.
See 7. c.
Three-phase pumps only:
Switch off the power supply with the
external circuit breaker, and
interchange two phases in the pump
terminal box.
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