Manitowoc Ice CM MODEL STH003 - Manual (Page 43)

43
ICE MACHINE WILL NOT HARVEST
1. Verify cubes are present in evaporator and freeze
time exceeds freeze chart cycle time.
•
Initial freeze cycle after resetting at toggle
switch will be 5 minutes longer than chart time
(refer to Sequence of Operation).
• Verify control board is not set for additional
freeze time to fill out the ice cubes, see cube
weight adjustment.
2. Observe control board light:
• Steady light indicates thermistor operation is
normal.
• Slow flash indicates a thermistor problem
(open or disconnected). Verify liquid line
thermistor is connected to control board,
securely attached to liquid line and insulated.
Refer to resistance chart and Ohm thermistor.
• Rapid flash indicates liquid line temperature
exceeded 170
°F (refer to discharge pressure
high checklist). If unable to determine cause,
refer to resistance chart and Ohm thermistor.
3. Reset ice machine.
• Wait freeze cycle time plus an addition 5
minutes (refer to Sequence of Operation).
4. Verify the water inlet valve is energized during the
entire harvest cycle and water flow is normal.
•
Although the hot gas valve is energized, the
ice machine will not consistently harvest if the
water inlet valve does not energize or has low
water flow.
5. Check for power at the hot gas valve
• Power is present - replace coil/valve.
• No power at hot gas valve - check for power
at circuit board connector, replace control
board if no power is present.