3
7. Maintenance
Make sure the pump is unplugged or, for three phase pumps the main switch is disconnected be-
fore carrying out any maintenance operations. Periodically check the delivery pressure and current
adsorption. A delivery pressure decrease may indicate pump wear or a blocked suction filter. In-
creased current absorption indicates abnormal mechanical friction in the pump or motor.
8. Troubleshooting
Fault
Possible Cause
Remedy
Pump fails to start
Power supply failure
Control panel fuse blown
MCB tripped
Reinstate incoming power supply
Replace power supply fuse
Reset MCB
Pump fails to stop
System pressure low due
to large leak
Switch unit off until leak is repaired
Pump switches on
and off quickly
Air in system
Vessel pre-charge incorrect
Purge air from pumps and pipework
Check vessel pre-charge and charge as
necessary with Nitrogen or dry air
Pump runs but will
not make pressure
Pump air locked
Non-return valve jammed
Incorrect rotation
Passing too much water
Suction filter blocked
Check pump is primed
Clean/ replace valve
Check phase sequence for three phase pump
Check system for leaks
Clean/ replace filter
Pump overheating
Pump partially seized
Remove pump and check for foreign objects
