Troubleshooting; Fault Finding Chart - Grundfos UP XL Installation And Operating Instructions Manual

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
1. The pump does not
run. None of the
indicator lights are
on.
2. The pump does not
run. The green
indicator light is on.
3. Noise in the system.
The green indicator
light is on.
4. Noise in the pump.
The green indicator
light is on.
5. The pump runs, but
the indicator light is
off.
6. Insufficient heat in
some places in the
heating system.
Cause
a) External circuit breaker
is switched off.
b) Current-/voltage-
operated ground fault
interrupter has tripped.
a) Rotor is blocked.
b) The speed switch is not
fully positioned (is
between speeds)
c) The pump has been cut
out by the thermal
overload switch due to
high liquid temperature.
a) Air in the system.
b) The pump flow is too
high.
c) The pressure is too
high.
a) Air in the pump.
b) The inlet pressure is
too low.
a) The LED diode was
damaged when
installing the terminal
box cover or is burned
out.
a) The pump performance
is too low.
b) The performance is too
high.
Remedy
Switch the circuit breaker on.
Repair the insulation defects and reset
the interrupter.
Switch off the electrical supply and clean
/repair the pump.
Switch off the electrical supply at the
external circuit breaker and change speed
switch into position.
Check that the liquid temperature falls
within the specified range. The pump will
restart automatically when it has cooled to
normal temperature.
Vent the system.
Reduce the pump performance.
Reduce the pump performance.
Vent the pump.
Increase the inlet pressure and/or check
the air volume in the expansion tank
(if installed).
Switch off the power and change the
printed circuit board or replace the
complete terminal box.
Increase the pump performance, if
possible. Flow too fast through the
boiler/heat exchanger may not allow for
the proper BTU transfer to the fluid. If fluid
is too slow, fluid may be cooling too much
before returning from the system. If
changing speeds does not resolve the
problem, replacing the pump with a
properly sized pump may be required.
11