Install Instructions

10
12. Fault finding chart
13. Disposal
This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest
Grundfos company or service workshop.
Warning
Before starting work on the pump, make sure that the power supply to the pump has been
switched off and that it cannot be accidentally switched on.
Fault Cause Remedy
1. Motor does not
start.
a) No power supply. Connect the power supply.
b) Motor switched off by float switch. Adjust/replace the float switch.
c) Fuses are blown. Replace fuses.
d) Motor protection/thermal relay has
tripped out.
Wait until the motor protection trips in
again/reset the relay.
e) Impeller blocked by impurities. Clean the impeller. See 10.2.
f) Short-circuit in cable or motor. Replace the defective part.
2. Motor protection/
thermal relay trips
out after short
time of operation.
a) Temperature of pumped liquid too high. Use another pump type.
b) Impeller blocked or partly blocked by
impurities.
Clean the impeller. See 10.2.
c) Phase failure. Call an electrician.
d) Voltage too low. Call an electrician.
e) Overload setting of the motor starter too
low.
Adjust the setting.
3. Pump runs
constantly or
gives insufficient
water.
a) Pump partly blocked by impurities. Clean the pump. See 10.2.
b) Discharge pipe or valve partly blocked by
impurities.
Clean the discharge pipe.
c) Impeller not properly fixed to the shaft. Tighten the impeller.
d) Incorrect setting of float switch. Adjust the float switch setting.
e) Pump too small for the application. Replace the pump.
f) Impeller worn. Replace the impeller.
4. Pump runs but
gives no water.
a) Pump blocked by impurities. Clean the pump. See 10.2.
b) Discharge pipe or non-return valve
blocked by impurities.
Clean the discharge pipe.
c) Impeller not properly fixed to the shaft. Tighten the impeller.
d) Air in pump. Vent the pump and the discharge
pipe.
e) Liquid level too low. The suction strainer
is not completely submerged in the
pumped liquid.
Submerge the pump in the liquid or
adjust the float switch.
f) Float switch does not move freely. Make the float switch move freely.
Subject to alterations.