Viking Range Error Code 20: Compressor Communication... | appliancefaults.com

Technical Background:

The Viking range's MCU monitors the compressor's operation through communication with the compressor control board. error code 20 indicates that the MCU is not receiving the expected signals from the compressor control board. This can be due to a variety of reasons, including a faulty control board, wiring problems, or a failed compressor. The MCU sends low voltage DC signals to the compressor control board which in turn switches 120VAC to the compressor.

Symptoms:

The homeowner reports that the Viking range displays error code 20 and the compressor is not running. The oven may not be heating properly or at all.

Possible Causes:

Defective compressor control board.
Wiring harness issue between the main control unit (MCU) and the compressor control board.
Failed compressor.
Power supply problem to the compressor control board.
MCU failure.
Loose wiring connections.

Solution:

1

Disconnect power to the range at the breaker panel.
2

Locate the compressor control board, typically behind the lower access panel. Access panels are usually held in place with 1/4-inch screws.
3

Inspect the wiring harness connecting the MCU to the compressor control board for any signs of damage, such as frayed wires or loose connections. Use a multimeter to check for continuity.
4

Check the voltage supply to the compressor control board. You should measure 120V AC at the appropriate terminals using a multimeter. If no voltage is present, troubleshoot the power supply circuit.
5

If voltage is present, replace the compressor control board.
6

If the issue persists after replacing the compressor control board, test the compressor windings for shorts or opens using a multimeter. Replace the compressor if necessary.
7

As a last resort, replace the MCU if all other components test good.

Safety Warning:

Disconnect power to the range at the breaker panel before performing any repairs. Lock Out Tag Out (LOTO) procedures must be followed. High voltage is present inside the range; exercise caution when working around electrical components.

Prevention:

Regularly inspect the range's wiring and connections for any signs of wear or damage. Ensure the range is properly ventilated to prevent overheating of components. Clean the range regularly to prevent grease buildup.

Expert Tip:

To enter service mode on some Viking ranges, press and hold the 'Bake' and 'Broil' buttons simultaneously for 5 seconds. This may allow you to run diagnostics and clear error codes.

Frequently Asked Questions

•How do I access the compressor control board on my Viking range?

The compressor control board is usually located behind the lower access panel. Remove the screws securing the panel to gain access.

•What voltage should I expect to see at the compressor control board?

You should measure 120V AC at the power input terminals of the compressor control board when the range is powered on and calling for compressor operation.

•How do I test the compressor windings for shorts or opens?

Use a multimeter set to the ohms setting. Disconnect the wires from the compressor terminals and measure the resistance between each terminal. Very low or zero resistance indicates a short, while infinite resistance indicates an open winding. Consult the service manual for acceptable resistance values.

Viking Range Error Code 20: Compressor Communication Failure Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the compressor control board on my Viking range?

•What voltage should I expect to see at the compressor control board?

•How do I test the compressor windings for shorts or opens?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: