Viking Oven Error Code Er21: Touch Panel Temperature Too... | appliancefaults.com

Technical Background:

The main control unit (MCU) monitors the temperature of the touch panel via a temperature sensor. The sensor sends a resistance signal to the MCU. The MCU interprets this resistance and displays the panel temperature. Er21 indicates that the MCU has registered a resistance value outside of the normal operating range, signaling an over-temperature condition. Voltage paths may be disrupted by shorts or open circuits in the wiring.

Symptoms:

Homeowners report the oven displaying the Er21 error code. The touch panel may feel unusually warm or hot to the touch. Oven operation may be interrupted, or the oven may refuse to heat.

Possible Causes:

Faulty touch panel temperature sensor
Defective control board (MCU)
Wiring harness issue between sensor and control board
Excessive heat exposure due to oven malfunction
Improper oven ventilation

Solution:

1

Disconnect power to the oven at the breaker panel (LOTO).
2

Locate the touch panel temperature sensor, typically on the back of the touch panel assembly. This may involve removing screws with a 1/4-inch nut driver to access the panel.
3

Using a multimeter, check the resistance of the sensor. Compare reading to the manufacturer's specifications (usually found in the service manual). An open or shorted sensor indicates a fault.
4

Inspect the wiring harness connecting the sensor to the control board for damage or loose connections. Use a wiring diagram to trace the connections.
5

Check the voltage supply to the control board using a multimeter. It should be 120V AC. Low voltage can cause erratic behavior.
6

If the sensor and wiring are good, replace the control board. This is a likely cause if the MCU is misinterpreting the sensor signal.
7

After repair, verify proper oven temperature calibration. Use an oven thermometer to ensure accurate heating.

Safety Warning:

Always disconnect power to the oven at the breaker panel before performing any repairs. Use Lock-Out/Tag-Out (LOTO) procedures to prevent accidental re-energizing. High voltage is present in the oven. Exercise extreme caution.

Prevention:

Ensure proper ventilation around the oven. Avoid using the oven for extended periods at high temperatures. Schedule regular appliance maintenance.

Expert Tip:

Many Viking ovens have a service mode. Consult the service manual for the exact sequence to enter service mode. Within service mode, you can often view real-time temperature readings from various sensors, which can aid in diagnosing the problem.

Follow-up Questions:

Frequently Asked Questions

•Where can I find the service manual for my Viking oven?

The service manual can often be found online by searching with your model number. Viking may also have it available on their website, or you can contact a certified Viking servicer to obtain a copy.

•How do I properly calibrate my Viking oven?

Oven calibration procedures vary by model. The service manual will provide specific instructions. Generally, it involves entering a service mode and adjusting an offset value to match the actual oven temperature.

•What is the typical resistance range for the touch panel temperature sensor?

The resistance range depends on the specific sensor used in your model. Consult the service manual or the sensor's datasheet for the correct values at different temperatures. If you can not find your exact model information assume it is a NTC thermistor with 10k ohms resistance @ 77°F (25°C).

Viking Oven Error Code Er21: Touch Panel Temperature Too High Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•Where can I find the service manual for my Viking oven?

•How do I properly calibrate my Viking oven?

•What is the typical resistance range for the touch panel temperature sensor?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: