SUB-ZERO ICBBI-42UFDID Over and Under Refrigerator or Freezer User Manual

SUB-ZERO ICBBI-42UFDID Over and Under Refrigerator or Freezer

ICBBI-42UFDID
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Troubleshooting

BUILT-IN GENERAL TROUBLESHOOTING
The General Troubleshooting chart lists general errors with troubleshooting suggestions. Some suggestions may refer to other sections in the manual.

UNIT TEMPERATURES AND THERMISTORS

Built-In Refrigerator Compartment Thermistor
The refrigerator compartment (r) thermistor senses the refrigerator compartment temperature and relays it to the control board.

Refrigerator Compartment Thermistor Test

1. urn off power to the unit.

2. Follow the procedure in Component Removal and
   Installation to expose the refrigerator cabinet thermistor.

3. Follow the procedure in Component Removal and
   Installation to expose the control board.

4. Remove the thermistor harness from the control board.

5. Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.

6. Measure the resistance of the thermistor through the control board connector.

7. If thermistor is outside the normal range of 30,000 to 33,000 ohms, replace it.

Built-In Refrigerator Evaporator Thermistor
The refrigerator evaporator (rE) thermistor senses the refrigerator evaporator temperature and transmits it to the control board.

Refrigerator Evaporator Thermistor Test

1. Turn off power to the unit.

2. Follow the procedure in Component Removal and
   Installation to expose the refrigerator evaporator thermistor.

3. Remove the thermistor from the refrigerator evaporator.

4. Follow the procedure in Component Removal and
   Installation to expose the control board.

5. Remove the thermistor harness from the control board.

6. Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.

7. Measure the resistance of the thermistor through the control board connector.

8. If thermistor is outside the normal range of 30,000 to 33,000 ohms, replace it.

Built-In Freezer Cabinet Thermistor
The freezer cabinet (F) thermistor senses the freezer cabinet temperature and transmits it to the control board.

Freezer Cabinet Thermistor Test

1. Turn off power to the unit.

2. Follow the procedure in Component Removal and
   Installation to expose the freezer cabinet thermistor.

3. Remove the thermistor from the freezer compartment clip.

4. Follow the procedure in Component Removal and
   Installation to expose the control board.

5. Remove the thermistor harness from the control board.

6. Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.

7. Measure the resistance of the thermistor through the control board connector.

8. If thermistor is outside the normal range of 30,000 to 33,000 ohms, replace it.

Built-In Freezer Evaporator Thermistor
The freezer evaporator (FE) thermistor senses the freezer evaporator temperature and transmits it to the control board, where it operates the evaporator fan.

Freezer Evaporator Thermistor Test

1. Turn off power to the unit.

2. Follow the procedure in Component Removal and
   Installation to expose the freezer evaporator thermistor.

3. Remove the thermistor from the freezer evaporator.

4. Follow the procedure in Component Removal and
   Installation to expose the control board.

5. Remove the thermistor harness from the control board.

6. Place the thermistor into an ice bath of 0°C. Let the
   thermistor sit for five minutes, stirring occasionally.

7. Measure the resistance of the thermistor through the control board connector.

8. If thermistor is outside the normal range of 30,000 to 33,000 ohms, replace it.

COMPONENT

Built-In Condenser Fan Testing
The control board monitors the power output to both compressors, and if either compressor is energized, the control board closes the condenser fan relay/triac and supplies the condenser fan with voltage. See the Technical Data section for condenser fan rating.

1. While the condenser fan is running, stop the condenser fan blade and determine if the condenser fan restarts. Repeat this test at least six times. If the condenser fan does not start or starts slowly, replace the condenser fan.
2. Disconnect the electrical connector from the condenser fan,and measure the resistance of the condenser fan. The resistance should be approximately 17 megaohms.
3. Connect the electrical connector and check for correct voltage on the hot lead on the condenser fan connector to ground.
4. Check for no voltage from the return lead on the condenser fan connector to ground.

Evaporator Fan Test – Direct Current
The evaporator fan has 12 VDC power at all times. Evaporator temperature determines the fan speed. See the Technical Data section for evaporator fan rating.

1. Verify the control board model configuration is correct.
2. Disconnect the electrical connector from the fan.
3. Measure the resistance between the power wire and the return wire.
4. Reconnect the fan.
5. Check for voltage between the power and return wires.
6. Check for voltage between the variable speed control and return wires.

Built-In Evaporator Fan Wiring
The evaporator fan uses a four-wire system to control fan operation. The four wires are fan power, variable speed control out, tachometer input, and fan return. Measuring the DC voltage between these wires should produce the following results.

Built-In Water Isolation Valve Test Procedure
Refer to the Water Flow diagram in this manual.
This procedure is for Built-In units above serial number 4380000.
On dispenser models, activating the dispenser confirms that the isolation valve is opening.

To measure the resistance of the isolation valve solenoid:

1. Turn off the power to the unit.
2. Disconnect the electrical leads from the isolation valve solenoid
   • On dual isolation valves, the solenoid is black with yellow fittings.
   • On the single isolation valve, the solenoid is brown with yellow fittings.
3. Measure the resistance between the isolation valve solenoid terminals. Compare the results with the Technical Data table.

Built-In Dispenser Valve Test Procedure
Refer to the Water Flow diagram in this manual.
This procedure is for Built-In units above serial number 4380000.
On dispenser models, activating the dispenser confirms that the dispenser valve is opening.
To measure the resistance of the dispenser valve solenoid:

1. Turn off the power to the unit.
2. Disconnect the electrical leads from the dispenser valve solenoid.
   • On dispenser models, the solenoid is tan with blue fittings.
3. Measure the resistance between the dispenser valve solenoid terminals. Compare the results with the Technical Data table.

Built-In Ice Maker Valve Test Procedure
Refer to the Water Flow diagram in this manual.
This procedure is for Built-In units above serial number 4380000.
To measure the resistance of the ice maker valve solenoid:

1. Turn off the power to the unit.
2. Disconnect the electrical leads from the ice maker valve solenoid.
   • On water valves, the ice maker solenoid is purple with yellow fittings.
3. Measure the resistance between the ice maker valve solenoid terminals. Compare the results with the Technical Data table.

Built-In Dispenser Water Valve Test Procedure
Refer to the Water Flow diagram in this manual.
This procedure is for Built-In units above serial number 4380000.

Built-In Defrost Heater Test Procedure

• This procedure is for Built-In units with a freezer above serial number 4380000.
• Confirm the defrost heater is working by activating the defrost system in manual component activation mode, which lasts for five minutes. See the instructions in the Controls and Operation section.
• The defrost heater operation can be confirmed by monitoring the evaporator temperature displayed on the control panel during defrost heater activation, or by removing the freezer air duct and viewing the defrost heater.

WARNING
DISCONNECT ELECTRICAL POWER TO ANY APPLIANCE COVERED IN THIS MANUAL BEFORE SERVICING. IF ELECTRICAL POWER IS NEEDED FOR COMPONENT TESTING OR DIAGNOSTICS, DISCONNECT ELECTRICAL POWER IMMEDIATELY AFTER TESTING OR DIAGNOSTICS ARE COMPLETED. FAILURE TO DO SO COULD CAUSE SERIOUS INJURY OR DEATH!
If the defrost heater is not activating, perform the following checks to find the issue.

BI-36UFDID and BI-42UFDID Drain Trough Heater Test Procedure
This test procedure is for the BI-36UFDID and BI-42UFDID models (including ICB) above serial number 4380000.
Confirm the drain trough heater is working by activating the defrost system in manual component activation mode. See the instructions in the Controls and Operation section of the service manual. Remove the freezer air duct to confirm that the drain trough heater is operating.
To measure the resistance of the drain trough heater:

1. Turn the power off to the unit.
2. Disconnect the drain trough heater harness from the defrost harness.
3. Measure the resistance between the drain trough heater terminals. Compare the results with the Technical Data table.
4. If the results are good, check the continuity across the drain trough heater connector.
5. If the results are bad, replace the drain trough heater.

SEALED SYSTEM

Sealed System Troubleshooting
Enter the sealed system to check pressures only if the Error Code Troubleshooting Guide and General Troubleshooting Guide do not pinpoint the cause of the temperature problem.

• Always use solder-on process valves when entering the sealed system. Do NOT use bolt-on process valves as they are prone to leak.
• When servicing the sealed system, always replace the high side filter drier.
• System pressures are listed in the Technical Data section of the service manual.
• Pressures listed are for reference only; actual pressure readings may vary because of ambient temperatures, temperature setpoints, food load, food temperature, condenser cleanliness, or gauge calibration.

Non-Functional, Inefficient, or Noisy Compressor

1. Always evacuate R600a refrigerant to the outdoors.
2. Use nitrogen for back-flushing the system.
3. Remove the compressor.
4. Replace the high-side filter drier.
5. Recharge the system with virgin R600a refrigerant.

High Side Leak

1. Always evacuate R600a refrigerant to the outdoors.
2. Use nitrogen for back-flushing the system.
3. Repair any leaks at the solder joint or replace the defective component.
4. Replace the high-side filter drier.
5. Bump or tap the compressor to help release residual refrigerant from the oil in the compressor.
6. Recharge the system with virgin R600a refrigerant.

Low Side Leak

1. Always evacuate R600a refrigerant to the outdoors.
2. Use nitrogen for back-flushing the system.
3. Repair any leaks at the solder joint or replace the defective component.
4. If all refrigerant escapes and the system is in a vacuum, replace the compressor.
5. Replace the high-side filter drier.
6. Recharge the system with virgin R600a refrigerant.

Contaminated Sealed System

1. Always evacuate R600a refrigerant to the outdoors.
2. Use nitrogen for back-flushing the system.
3. Repair any leaks at the solder joint, or replace the defective component.
4. Replace the compressor.
5. Replace the high-side filter drier.
6. Replace the evaporator or heat exchanger assembly if the cap tube clogs.
7. Install a low-side drier on the suction line.
8. Recharge the system with virgin R600a refrigerant.

Sealed System Restriction
IMPORTANT NOTE: If a restriction is due to the sealed system being contaminated, see Contaminated Sealed System.

1. Always evacuate R600a refrigerant to the outdoors.
2. Locate and remove the restriction or locate and replace the part.
3. Use nitrogen for back-flushing the system.
4. Replace the high-side filter drier.
5. Bump or tap the compressor to help release residual refrigerant from the oil in the compressor.
6. Recharge the system with virgin R600a refrigerant.

Sealed System Refrigerant Overcharge

1. Always evacuate R600a refrigerant to the outdoors.
2. Use nitrogen for back-flushing the system.
3. Replace the high-side filter drier.
4. Bump or tap the compressor to help release residual refrigerant from the oil in the compressor.
5. Recharge the system with virgin R600a refrigerant.

References

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