Fault Finding Chart - Grundfos ALPHA2 L Series Installation And Operating Instructions Manual

1. The pump Light off.
does not run.
"POWER
ON" is on
only.
2. Noise in the "POWER
system. "ON" and the
light field for
pump setting
are on.
3. Noise in the "POWER
pump. "ON" and the
light field for
pump setting
are on.
4. Insufficient "POWER
heat. "ON" and the
light field for
pump setting
are on.
a) One fuse in the
installation is blown.
b) The current-operated or
voltage-operated circuit
breaker has tripped out.
c) The pump is defective.
a) Electricity supply failure.
Might be too low.
b) The pump is blocked.
a) Air in the system.
b) The flow is too high.
a) Air in the pump.
b) The inlet pressure is too
low.
a) The pump performance
is too low.
22
Replace the fuse.
Cut in the circuit breaker.
Replace the pump.
Check that the electricity supply
falls within the specified range.
Remove the impurities.
Vent the system.
See
.
Reduce the suction head.
See
.
Let the pump run. It vents itself
over time.
See
Increase the inlet pressure or
check the air volume in the
expansion tank, if installed.
Increase the suction head.
See
.
.