Viking Fridge Error Code 8 Flashes: Defrost System... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) monitors the defrost system components. The MCU supplies 120V AC to the defrost heater through a defrost thermostat or thermistor. If the MCU does not sense the proper temperature change or heater current draw within a specific timeframe, it flags error code 8.

Symptoms:

The homeowner notices ice buildup in the freezer, the refrigerator may not be cooling properly, and the error code 8 (eight flashes) is displayed.

Possible Causes:

Defective defrost heater
Faulty defrost thermostat or thermistor
Failed defrost timer or electronic control board
Wiring harness issues in the defrost circuit
Blocked defrost drain

Solution:

1

Disconnect power to the refrigerator at the breaker panel. Verify 0V AC at the fridge outlet before proceeding.
2

Locate the defrost heater, usually behind the evaporator coil inside the freezer compartment. Use a multimeter to test the heater for continuity. An open circuit indicates a failed heater. Replace if necessary.
3

Identify the defrost thermostat or thermistor, typically attached to the evaporator coil. Test for continuity at room temperature (around 70°F). It should be closed. If open, replace it.
4

Access the main control board. Visually inspect for burnt components or damaged traces. If there is visible damage or if heater and thermostat are good, replace the control board.
5

Check the wiring harness for any loose connections or damaged wires related to the defrost circuit. Repair or replace as needed.
6

Check the defrost drain for ice blockage. Use a steamer or hot water to clear any obstructions. Ensure proper drainage.
7

Restore power and monitor the refrigerator's operation. Verify the error code clears.

Safety Warning:

Lock Out/Tag Out (LOTO) the refrigerator at the breaker panel before performing any repairs. High voltage is present in the control board and defrost circuit. Exercise caution.

Prevention:

Regularly inspect and clean the defrost drain. Avoid overfilling the freezer, which can restrict airflow and contribute to ice buildup. Consider a preventative maintenance check every 12-18 months.

Expert Tip:

Some Viking refrigerators have a service mode that allows you to manually initiate a defrost cycle. Consult the service manual for the specific key sequence for your model. This can help isolate the problem if the defrost cycle isn't starting automatically.

Frequently Asked Questions

•Where is the defrost timer located on my Viking refrigerator?

The defrost timer may be integrated into the electronic control board. Refer to the unit's service manual for the exact location on your specific model. Some older units may have an electromechanical timer typically located behind the control panel or near the compressor compartment.

•What is the resistance value I should expect from the defrost heater?

The resistance of the defrost heater depends on its wattage. A typical value is between 20-50 ohms. A significantly higher or infinite resistance indicates a faulty heater.

•How do I access the service mode on my Viking refrigerator?

Service mode access varies by model. Generally, it involves a specific sequence of button presses on the control panel. Consult the technical service literature for your model to find specific instructions.

Viking Fridge Error Code 8 Flashes: Defrost System Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•Where is the defrost timer located on my Viking refrigerator?

•What is the resistance value I should expect from the defrost heater?

•How do I access the service mode on my Viking refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: