Fault
Grundfos Eye
Indicator light
Automatic reset
Cause Remedy
System overpres-
sure.
Yes
The setpoint is set too high. The differ-
ence between the outlet pressure and
the inlet pressure must not exceed 3.5
bar (51 psi).
Reduce the pressure to a new setpoint
(maximum 3.5 bar (51 psi) + positive inlet
pressure).
Example: If the inlet pressure is 0.5 bar (7
psi), the maximum outlet pressure is 4 bar
(58 psi).
Yes
The maximum pressure has been ex-
ceeded, the inlet pressure is higher
than 6 bar, 0.6 MPa (87 psi).
Check the inlet conditions.
Yes
The maximum pressure has been ex-
ceeded. Equipment elsewhere in the
system causes a high pressure at the
pump, for example water heater or de-
fective safety equipment.
Check the installation.
You can reset the
pump, but it runs
only for a few sec-
onds.
Yes Dry running or water shortage.
Check the water source, and prime the
pump.
Yes The inlet pipe is blocked by impurities. Clean the inlet pipe.
Yes
The foot or non-return valve is blocked
in closed position.
Clean, repair or replace the foot or non-re-
turn valve.
Yes There is a leakage in the inlet pipe. Repair the inlet pipe.
Yes Air in the inlet pipe or the pump.
Prime the inlet pipe and the pump. Check
the inlet conditions of the pump.
You can reset the
pump, but it starts
repeatedly, imme-
diately after stop-
ping.
No
The internal non-return valve is defec-
tive or blocked in completely or partly
open position.
Clean, repair or replace the non-return
valve.
No
The tank precharge pressure is not cor-
rect.
Adjust the tank precharge pressure to 70
% of the required outlet pressure.
Related information
11. Servicing the product
12. Starting up the product after standstill
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English (GB)