Cause
A tap has not been entirely closed after use.
Remedy
Make sure all taps are closed.
Cause
There is a minor leakage in the system.
Remedy
Make sure there are no leakages in the system.
8.4.3 The "Alarm" indicator light is permanently on
Cause
Dry running. The pump needs water.
The pump has stopped due to the dry-running
function.
Remedy
Make sure that the water supply is sufficient.
Cause
The power supply to the pump is disconnected.
Remedy
Check the plug and cable connections, and make
sure that the built-in circuit breaker of the pump is
switched off.
Cause
The motor protection of the pump has tripped
due to overload.
Remedy
Make sure the motor or pump is not blocked.
Cause
The pressure manager is defective.
Remedy
Repair or replace the pressure manager.
Find more information in the service instructions
at
https://product-selection.grundfos.com
8.4.4 The "Power on" indicator light is off even though the
power supply has been switched on
Cause
The fuses in the electrical installation have
blown.
Remedy
Replace the fuses. If the new fuses also blow,
check the electrical installation for malfunctions.
Cause
The earth-leakage circuit breaker or the voltage-
operated circuit breaker has tripped.
Remedy
Cut in the circuit breaker.
Cause
The pressure manager is defective.
Remedy
Repair or replace the pressure manager.
Find more information in the service instructions
at
https://product-selection.grundfos.com
8.4.5 The "Pump on" indicator light is on, but the pump does
not start
Cause
The power supply to the pump is disconnected.
Remedy
Check the plug and cable connections, and make
sure that the built-in circuit breaker of the pump is
switched off.
Cause
The motor protection of the pump has tripped
due to overload.
Remedy
Make sure the motor or pump is not blocked.
Cause
The pump is defective.
Remedy
Repair or replace the pump.
Cause
The pressure manager is defective.
Remedy
Repair or replace the pressure manager.
Find more information in the service instructions
at
https://product-selection.grundfos.com
8.4.6 The pump does not start when water is consumed
The "Pump on" indicator light is off.
Cause
There is too big a difference in height between
the pressure manager and the tapping point.
Remedy
Adjust the installation, or increase the start
pressure.
Cause
The pressure manager is defective.
Remedy
Repair or replace the pressure manager.
Find more information in the service instructions
at
https://product-selection.grundfos.com
.
8.4.7 The pump does not stop
Cause
The pump cannot deliver the necessary outlet
pressure.
Remedy
Replace the pump.
Cause
The start pressure is set too high.
Remedy
•
PM 1: The start pressure is factory set. Make
sure that your product is dimensioned correctly.
•
PM 2, PM TWIN: Decrease the start pressure.
Cause
The non-return valve is stuck in open position.
Remedy
Clean or replace the non-return valve.
Cause
The pressure manager is defective.
Remedy
Repair or replace the pressure manager.
Find more information in the service instructions
at
https://product-selection.grundfos.com
.
8.5 Fault finding boosters with a pressure tank
8.5.1 The booster starts and stops too frequently
Cause
Incorrect precharge pressure.
Remedy
Adjust the diaphragm tank pressure.
Cause
Leakage in pipes.
Remedy
Check and repair the pipes.
Cause
The diaphragm is broken. Water escapes if the
air valve is pushed down.
Remedy
Replace the pressure tank.
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English (GB)
