Viking Oven Error Code S-r: Troubleshooting and Service... | appliancefaults.com

Technical Background:

error code S-r on a Viking oven typically indicates a problem with the oven temperature sensor or the oven control board. The MCU (Microcontroller Unit) on the control board monitors the resistance of the RTD (Resistance Temperature Detector) sensor to determine the oven temperature. When the MCU detects an abnormal resistance reading or a break in the sensor circuit, it triggers the S-r error. The voltage path involves a low-voltage DC signal from the MCU to the RTD, and a return signal based on the resistance back to the MCU.

Symptoms:

The homeowner reports that the Viking oven displays error code S-r on the control panel and the oven may not heat up properly, or at all. They might have also noticed that the oven is taking longer than usual to preheat, or that the temperature fluctuates erratically.

Possible Causes:

Defective oven temperature sensor (RTD).
Faulty oven control board (MCU).
Wiring harness issue between the sensor and the control board.
Overheating condition inside the oven cavity.
Software glitch in the control board’s firmware.

Solution:

1

Disconnect power to the Viking oven at the breaker panel. Use a multimeter to verify that power is off.
2

Locate the oven temperature sensor (RTD) inside the oven cavity, usually at the rear. Check for physical damage.
3

Disconnect the sensor wires from the control board. Using a multimeter set to ohms, measure the resistance of the sensor at room temperature (approximately 70-75°F). Compare the reading to the manufacturer's specifications. Typically, it should be around 1080-1100 ohms.
4

Inspect the wiring harness connecting the sensor to the control board for any loose connections, frayed wires, or corrosion. Use a wire stripper and crimp connectors to repair any damaged wiring.
5

Visually inspect the oven control board for any signs of burned components or damage. If damage is apparent, replace the control board.
6

If the sensor and wiring are good, and the control board appears functional, try resetting the oven by disconnecting power for 5 minutes, then reconnecting it.
7

If the error persists after all other steps, the control board requires replacement.

Safety Warning:

Always disconnect power to the oven at the breaker panel before performing any troubleshooting or repairs. Follow Lock-Out/Tag-Out (LOTO) procedures to prevent accidental re-energizing of the circuit. The oven control board may contain high-voltage components, so exercise caution when working around it.

Prevention:

Regularly clean the oven to prevent excessive buildup of grease and food particles, which can lead to overheating and sensor damage. Avoid using harsh chemicals when cleaning, as they can damage the sensor and wiring. Periodically check the wiring harness for any signs of wear and tear.

Expert Tip:

Many Viking ovens have a service mode that allows you to run diagnostic tests on the temperature sensor and other components. To access service mode, typically you need to press and hold two specific buttons simultaneously (often the bake and broil buttons) for several seconds. Check the service manual for your specific model for the correct sequence.

Frequently Asked Questions

•What is the typical resistance range for a Viking oven RTD sensor at different temperatures?

The resistance of an RTD sensor varies with temperature. At room temperature (70-75°F), it's typically around 1080-1100 ohms. Refer to the Viking service manual for the exact resistance values at specific temperatures for your model.

•How do I properly test the wiring harness for continuity and shorts?

Disconnect the wiring harness from both the sensor and the control board. Use a multimeter set to the continuity setting to check for continuity between each wire in the harness. Then, use the multimeter set to ohms to check for shorts between each wire and the oven chassis. Any continuity issues or shorts indicate a wiring problem that needs to be addressed.

•Where can I find a reliable source for replacement parts for my Viking oven?

Authorized Viking parts distributors are the most reliable source for replacement parts. You can find a list of authorized distributors on the Viking website or by contacting Viking customer service. Ensure you provide the full model and serial number of your oven to ensure you receive the correct parts.

Viking Oven Error Code S-r: Troubleshooting and Service Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range for a Viking oven RTD sensor at different temperatures?

•How do I properly test the wiring harness for continuity and shorts?

•Where can I find a reliable source for replacement parts for my Viking oven?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: