Sub-Zero UC-15I Service Manual page 64

Troubleshooting
PROBLEM
(Continued from last page)
B. Ice Machine Operates, but
Will Not Make Ice
#7012423 - Revision A - August, 2009
Model UC-15I (Undercounter Ice Machine)
POSSIBLE CAUSE
No Water in Water Trough
No Water Spray from Spray Nozzles
No Airflow Through Condenser
Hot Gas Valve Stuck Open
Liquid Line Thermistor Fault
(Disconnected, Open or Misread)
Compressor Electrical Fault
Sealed System Fault
6-4
TEST / ACTION
a. Water supply is off. Turn water supply on.
b. Check water supply line for kinks or restric-
tions. Replace defective supply line.
c. Check water filter. Replace if clogged.
d. Check screens in water valve for obstruc-
tions. Clean screens or replace valve.
e. Check for loose or disconnected wiring to
water valve. Repair bad wiring.
f. Check water valve integrity / operation.
Replace if defective.
g. Check trough for leak. Reposition/replace
trough.
h. Check standpipe. Reposition or replace.
a. Check for blockage in spray nozzles. See
Maintenance, Cleaning and Adjustment
Information section of service manual.
b. Check trough for leak. Reposition/replace.
c. Check for loose or disconnected wiring to
spray pump. Repair or reconnect wiring.
d. Check operation of spray pump. Replace
if defective.
a. Check for obstructions in vents of kick-
plate. Move/clear obstruction.
b. Check condenser. Clean if dirty.
c. Check for loose or broken condenser fan
blade. Repair or replace blade.
d. Check condenser fan motor wire connec-
tions. Repair or reconnect wiring.
e. Check operation of condenser fan motor.
Replace if defective.
Check operation of hot gas valve. Replace
valve and drier if valve is defective.
a. Check connection at board. Reconnect.
b. Check for 30K - 33K ohms at ~32°F / 0°C
or 8K - 12K ohms at ~77°F / 25°C.
Replace if defective.
NOTE: A slow flashing light at control board
indicates thermistor open or disconnected. A
rapid flashing light indicates temperatures
exceeded 170°F (77°C); look for cause and/or
check thermistor resistance.
a. Check compressor electricals for loose or
disconnected wiring. Repair or reconnect.
b. Check operation of overload and relay. If
defective, replace.
a. If power is at compressor and electricals
are good, but compressor will not run,
replace compressor and drier.
b. Inspect sealed system for leaks, restric-
tions or inefficient compressor by observ-
ing frost patterns and feel tubing for irregu-
lar temperatures. Repair or replace com-
ponents as needed.