Install Instructions

10
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6. Troubleshooting
6.1 Fault finding chart
Warning
Before removing the terminal box cover, make sure that the electrical supply has
been switched off and that it cannot be accidentally switched on.
The pumped liquid may be scalding hot and under high pressure. Before any removal
or dismantling of the pump, the system must be drained or the isolation valves on
both sides of the pump must be closed.
Fault Cause Remedy
1. The pump does
not run.
None of the
indicator lights
are on.
a) One fuse in the installation
is blown.
Replace the fuse.
b) External circuit breaker is
switched off.
Switch the circuit breaker on.
c) Current-/voltage-operated
ground fault interrupter
has tripped.
Repair the insulation defects and reset the
interrupter.
d) The pump's internal ther-
mal overload switch has
cut out (standard module
only).
Check that the liquid temperature falls
within the specified range.
With external on/off changeover
contact:
The pump will restart automatically when it
has cooled to normal temperature.
With external on/off impulse contacts:
The pump can be restarted when it has
cooled to normal temperature.
2. The pump does
not run.
The green
indicator light is
on.
a) Rotor blocked, but the
pump hasn't been cut out
by the thermal overload
switch.
Switch off the electrical supply and
clean/repair the pump.
b) The speed switch module
has not been fitted.
Switch off the electrical supply at the
external circuit breaker and fit the speed
switch module into position.
3. Three-phase
pumps only:
The pump is
running.
The red and
green indicator
lights are on.
a) The pump is running with
the wrong direction of rota-
tion.
Switch off the electrical supply at the
external circuit breaker and interchange
any two phases (leads) in the pump
terminal box.
4. Noise in the
system. The
green indicator
light is on.
a) Air in the system. Vent the system.
b) The pump flow is too high. Reduce the pump performance.
c) The pressure is too high. Reduce the pump performance.
5. Noise in the
pump. The green
indicator light is
on.
a) Air in the pump. Vent the pump.
b) The inlet pressure is too
low.
Increase the inlet pressure and/or check
the air volume in the expansion tank (if
installed).
6. Insufficient heat
in some places
in the heating
system.
a) The pump performance is
too low.
Increase the pump performance, if
possible, or replace the pump with a pump
with higher flow.