Viking Refrigerator Error Code dH: Defrost Heater Open... | appliancefaults.com

Technical Background:

The main control unit (MCU) monitors the defrost heater circuit. It applies 120V AC to the heater during the defrost cycle. The MCU detects the current flow through the heater. If the MCU detects an open circuit, it triggers the dH error code. The defrost thermostat acts as a safety device, preventing the heater from overheating.

Symptoms:

The refrigerator is displaying error code dH. The freezer may be icing up excessively, and the refrigerator compartment may be warmer than usual. The defrost cycle is not functioning, leading to ice buildup on the evaporator coils.

Possible Causes:

Defective defrost heater
Faulty defrost thermostat
Wiring harness damage (open circuit)
Defective main control board (MCU)
Loose wiring connections

Solution:

1

Disconnect power to the refrigerator at the breaker panel.
2

Locate the defrost heater, usually behind the evaporator coil cover in the freezer. Access may require removing shelves and panels using a 1/4-inch nut driver.
3

Visually inspect the heater for breaks or damage. Check the defrost thermostat for continuity using a multimeter; it should show continuity when cold. Use a wire jumper to bypass thermostat for testing purposes ONLY.
4

Use a multimeter to test the defrost heater's resistance. An open circuit (OL) indicates a failed heater. A typical heater resistance is between 20-50 Ohms.
5

Inspect the wiring harness and connectors for damage or loose connections. Use a wiring diagram to ensure proper connections.
6

If the heater and wiring are good, suspect a faulty main control board. Replace the control board if other components test properly.
7

Reassemble the refrigerator and restore power. Monitor for proper operation and code clearance.

Safety Warning:

Disconnect power to the refrigerator before performing any repairs. Lock Out/Tag Out (LOTO) the breaker. Some components may carry 120V AC when the refrigerator is powered on. Wear appropriate personal protective equipment (PPE).

Prevention:

Periodically inspect the freezer compartment for excessive ice buildup. Ensure proper door seals to prevent moisture intrusion. Consider licensed technician maintenance checks every 1-2 years.

Expert Tip:

Some Viking models have a service mode that allows you to manually activate the defrost cycle. This can be used for diagnostic purposes. Consult the service manual for the specific model's service mode entry sequence. The defrost cycle typically runs for 20-30 minutes.

Frequently Asked Questions

•What is the typical resistance range for a Viking refrigerator defrost heater?

A typical resistance range is between 20-50 Ohms. An open circuit (OL) indicates a failed heater.

•How do I enter service mode on my Viking refrigerator to manually activate the defrost cycle?

The service mode entry sequence varies by model. Consult the service manual or technical data sheet for your specific Viking refrigerator model.

•Where is the defrost thermostat located in a Viking refrigerator?

The defrost thermostat is typically located near the defrost heater, behind the evaporator coil cover in the freezer compartment. It is usually clipped to the evaporator coil.

Viking Refrigerator Error Code dH: Defrost Heater Open Circuit Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range for a Viking refrigerator defrost heater?

•How do I enter service mode on my Viking refrigerator to manually activate the defrost cycle?

•Where is the defrost thermostat located in a Viking refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: