Sub-Zero UC-15I Service Manual page 65

Model UC-15I (Undercounter Ice Machine)
PROBLEM
C. Ice Machine Makes Ice, but
Cubes Do Not Release
from Mold
D. Slow/Low Ice Production
(Continued on next page)
POSSIBLE CAUSE
Mineral Scale Build-up in Ice Making
System
Freeze Time Too Long
Hot Gas Valve or Solenoid Fault
Liquid Line Thermistor Fault
(Disconnected, Open or Misread)
Control Board Fault
Heavy/Frequent Ice Consumption
Improper Ambient Temperatures
Improper Water Temperatures
Poor or No Airflow Through Condenser
Bin Drain Restricted, Melting Ice in Bin
6-5
TEST / ACTION
See Maintenance, Cleaning and Adjustment
Information section of service manual.
See Cube Weight Check and Adjustment in
Maintenance, Cleaning and Adjustment
Information section of service manual.
a. Check for loose or disconnected wiring to
hot gas valve solenoid. Repair bad wiring.
b. Check integrity of solenoid coil. Replace if
open or shorted.
c. Check operation of hot gas valve. If stuck,
replace valve and drier.
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.
Check for power at control board to hot gas
valve during harvest cycle. If no power is
present, replace board.
12 - 24 hours to fill bin is normal. Heavy/fre-
quent ice consumption will slow refill process.
Advise customer.
Ambient air temperature minimum = 50°F
(10°C), maximum = 100°F (38°C) for models
UC-15I and UC-15IP; 110°F (43°C) for models
UC-15IO and UC-15IPO. Advise customer.
NOTE: Check control board light to see if ice
machine shutdown on over temperature limit
(control board light will flash rapidly).
Water temperature minimum = 50°F (10°C),
maximum = 80°F (27°C). Ice production slows
with warmer water. Advise customer.
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.
Clean out bin drain and/or check installation
for kinks in drain line.
#7012423 - Revision A - August, 2009
Troubleshooting