Fault Finding Chart; Disposal - Grundfos ALPHA Pro Installation And Operating Instructions Manual

9. Fault finding chart

Before starting any work on the pump, make sure that the electricity supply has been switched off
and that it cannot be accidentally switched on.
Fault Display
Light off.
Pump not
running.
Shows "- -".
Noise in the Shows
system. a number.
Noise in the Shows
pump. a number.
Insufficient
heat in some
Shows
places in the
a number.
heating sys-
tem.

10. Disposal

This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest
Grundfos company or service workshop.
10
Cause
One fuse in the installation
is blown.
The current-operated or
voltage-operated circuit
breaker has tripped out.
Pump defective.
Electricity supply failure.
Might be too low.
Pump blocked.
Air in the system.
The flow is too high.
Air in the pump.
The inlet pressure is too
low.
Pump performance too low.
Remedy
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.
Reduce the suction head by turning the
selector switch counter-clockwise, see
section 7.2 Change of head setting.
Let the pump run. It vents itself over time.
The selector switch can be turned to posi-
tion III to speed up the venting. Set the se-
lector switch back to the desired position
after approx. 10 minutes.
Increase the inlet pressure or check the air
volume in the expansion tank (if installed).
Increase the suction head by turning the
selector switch clockwise, see section
7.2 Change of head setting.
Subject to alterations.