Fault Finding Chart - Grundfos CM PM1 Guía Rápida

7. Fault finding chart

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
1. The green a)
"Power on"
indicator light
b)
is off.
c)
d)
2. The green a)
"Pump on"
indicator light
is on, but the
b)
pump does not
start.
c)
d)
3. The pump a)
does not start
when water is
consumed.
b)
The "Pump
on" indicator
light is off.
4. Frequent a)
starts/stops.
b)
c)
5. The pump a)
does not stop.
b)
c)
d)
6. The red a)
"Alarm"
indicator light
b)
is permanently
on.
c)
d)
e)
7. The red a)
"Alarm"
indicator light
is flashing.
10
The fuses in the electric installation
have burnt.
The earth leakage circuit breaker or
the voltage-operated circuit breaker
has tripped out.
No power supply.
The PM unit is defective.
The power supply to the pump is
disconnected after the PM unit.
The motor protection of the pump
has tripped out due to overload.
The pump is defective.
The PM unit is defective.
Too big difference in height
between the PM unit and the
tapping point.
The PM unit is defective.
Leakage in the pipework.
Leaky non-return valve.
A valve close to the PM 1 outlet has
been closed.
The pump cannot deliver the
necessary discharge pressure.
A PM unit with too high start
pressure is installed.
The PM unit is defective.
The non-return valve is stuck in
open position.
Dry running. The pump needs
water.
The power supply to the pump is
disconnected after the PM unit.
The motor protection of the pump
has tripped out due to overload.
The pump is defective.
The PM unit is defective.
Cycling. A tap has not been closed
entirely after use.
Remedy
Replace the fuses. If the new fuses also
burn, check the electric installation.
Cut in the circuit breaker.
Contact the power supply authorities.
Repair or replace the PM unit.
Check the plug and cable connections, and
check if the built-in circuit breaker of the
pump is switched off.
Check if the motor/pump is blocked.
Repair or replace the pump.
Repair or replace the PM unit.
Adjust the installation, or select a PM unit
with a higher start pressure.
Repair or replace the PM unit.
Check and repair the pipework.
Clean or replace the non-return valve.
Open the valve.
Replace the pump.
Select a PM unit with a lower start pressure.
Repair or replace the PM unit.
Clean or replace the non-return valve.
Check the pipework.
Check the plug and cable connections, and
check if the built-in circuit breaker of the
pump is switched off.
Check if the motor/pump is blocked.
Repair or replace the pump.
Repair or replace the PM unit.
Check that all taps have been closed.