Grundfos SCALA Installation And Operating Instructions Manual page 19

Fault
2. The pump is
running.
3. Pump
performance
is insufficient.
Cause
a) Leakage from the
pipework, or the
- non-return valve is not
properly closed due to
impurities
b) Small continuous
consumption
-
c) The temperature is below
freezing point
-
a) The pump inlet pressure
is too low
- -
b) The pump is undersized.
-
c) The inlet pipe, the inlet
strainer or the pump is
- -
partly blocked by
impurities
d) Leakage in the inlet pipe
- -
e) Air in the inlet pipe or the
pump
- -
f) The required outlet
pressure is too low for the
- -
installation
g) The maximum
temperature has been
Yes exceeded and the pump
is running at reduced
performance
Remedy
Check and repair the
pipework, or clean,
repair or replace the
non-return valve.
Check the taps and
reconsider the usage
pattern (ice machines,
water evaporators for
air-conditioning, etc.).
Consider protecting the
pump and the installation
against frost.
Check the inlet
conditions of the pump.
Replace the pump with a
bigger pump.
Clean the inlet pipe or
the pump.
Repair the inlet pipe.
Prime the inlet pipe and
the pump.
Check the inlet
conditions of the pump.
Increase the pressure
setting (arrow up).
Check the cooling
conditions. Protect the
pump against direct
sunlight or any nearby
heat sources.
19