English (GB)
20
9.2 Fault indications
The fault indication below can be read by means of the number in 
brackets, as text or as status indications on the control panel, 
depending on the equipment available.
Grundfos Eye Condition/cause Remedy
Two opposite red indicator lights 
flashing simultaneously.
External fault (3)
An external signal has reported an 
"External fault" to the digital input set up 
for this function.
Check the parameter or the unit reporting the 
external fault. Correct the fault.
Too many restarts (4)
The pump has restarted to many times in 
connection with a fault that forced the 
pump to stop and restart automatically.
a) Check the warning and alarm log for faults that 
caused to many restarts.
b) Replace the pump if the fault cannot be found.
Overvoltage (32)
Supply voltage to the pump too high.
a) Check that the power supply is within the 
specified range.
Undervoltage (40)
Supply voltage to the pump too low. a) Check that the power supply is within the 
specified range.
Overload (49)
The motor is overloaded and has 
automatically reduced the speed and thus 
the pump performance.
a) Check that the viscosity and temperature of the 
pump liquid is within the limits for the pump. If 
not, change the properties of the liquid.
b) Dismantle the pump, and remove any foreign 
matter or impurities preventing the pump from 
rotating.
c) If none of the above causes are present, 
replace the pump.
Blocked pump (51)
The pump is blocked.
a) Dismantle the pump, and remove any foreign 
matter or impurities preventing the pump from 
rotating.
One yellow indicator light permanently 
on.
Pump communication fault (10)
Communication fault between this pump 
and the other pumps of the multipump 
system.
a) Check that all pumps of the multipump system 
have been correctly set up. 
Forced pumping (29)
Other pumps or sources force flow 
through the pump even if the pump is 
stopped.
a) Check the system for defective non-return 
valves and replace, if necessary. Check the 
system for correct position of non-return valves, 
etc.
Dry running (56, 57)
No water at the pump inlet or the water 
contains too much air.
a) Prime and vent the pump before a new start-up. 
Check that the pump is operating correctly. If 
not, replace the pump.
Internal fault (72, 83, 85, 155, 157, 163)
Internal fault in the pump electronics.
a) Replace the functional module, power module 
or terminal box.