Temperature Sensors
1. Check controller. If the sensor calibration is completely out of range, the code display will read either 5
or 7.
2. Check with an ohmmeter. Open control box cover, unplug sensor from J6. Water temperature probe:
Measure the temperature of the water. Push and release the clean button. Wait one minute. Measure the
resistance of the water probe (two leads next to the open socket) and compare to the resistance in the
chart for that temperature. Any reading within 1000 ohms is acceptable. Discharge sensor: Measure the
temperature of the discharge line as close to the sensor as possible. Measure the resistance of the
discharge temperature sensor (two leads farthest away from the open socket on the harness connector)
and compare to the resistance in the chart for that temperature. Any reading within 1000 ohms is
acceptable.
3. Alternate procedure: Remove both water and discharge sensors from their places on the ice machine.
Put both into a container of ice water. Put a thermometer in the water. When the thermometer is at 32
degrees F., check the resistance of each sensor. The resistance should be within 1000 ohms of 32649.
November 2010
Page 26
C2648 Service Manual
Water
Temperature
Discharge
Temperature
Back of Controller
