Scotsman NU150 - Page 16

NUUndercounterIceMakerUserManual TroubleshootingTable
B14
Symptom Possible Cause Suggested Correction
Irregular cube
sizes and some
cloudy cubes
Spray bar blocked Clean the spray bar
Shortage of water
See the processing method for
water-shortage
Machine not level Level the machine as required
Water temperature sensor failure Replace the water temperature sensor
Decreased ice
capacity
Inefficient compressor Replace the compressor
Water valve leak Check, if damaged, replace it
Spray pipe blocked Check, if blocked, clean it.
Non-condensable gas in system Vacuum and re-charge
Bad ventilation Improve ventilation or put the machine
in a good ventilation place
Too much dust on air filter Clean the air filter, if needed, replace it.
Expansion valve partially blocked Check, if damaged, replace it
Defrost valve leaking Change charged volume, release
slowly
Refrigerant over charge
Shortage of refrigerant
Vacuum and re-charge according to the
nameplate
Discharge pressure too high or
too low
Check for the cause of the incorrect
discharge pressure
Defrost valve blocked or not
open
Check, if damaged, replace it
Unit doesn’t defrost
or no ice
PC board failure Check, if damaged, replace it
Defrost valve not opening Check, if damaged, replace it
Water inlet solenoid valve not
opening
Check, if damaged, replace it
Incorrect discharge
pressure
Inoperative condenser sensor Check, if damaged, replace it
Too much or too little refrigerant,
or non-refrigerant gas was
charged
Check whether the refrigeration system
is leaking
Vacuum and re-charge according to the
nameplate and the requirements from
Scotsman
Inoperative PC board Check, if damaged, replace it
Excessive water at
unit base
Water system leak
Check for leaking points and repair
them. If necessary, replace it.