Kenmore Oven Error Code F3: Troubleshooting Oven... | appliancefaults.com

Technical Background:

The oven control board (MCU) monitors the oven temperature using the oven temperature sensor (RTD or Thermistor). The sensor's resistance changes with temperature. The MCU sends a low voltage signal through the sensor circuit and interprets the returning voltage. An open circuit (very high resistance) disrupts this signal, causing the MCU to display error code F3.

Symptoms:

The Kenmore oven displays error code F3 and is unable to maintain the set temperature. The oven may not heat at all, or it may heat erratically. The error code appears shortly after starting the oven or during the preheating cycle.

Possible Causes:

Faulty oven temperature sensor (RTD/Thermistor)
Wiring harness damage or loose connections
Defective oven control board (MCU)
Sensor not fully inserted into the oven cavity
Corrosion on sensor terminals or wiring connectors

Solution:

1

Disconnect power to the oven at the breaker panel. Verify 0V AC at the oven receptacle with a multimeter.
2

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

Disconnect the sensor wires from the oven control board (MCU). The MCU is typically located behind the control panel.
4

Using a multimeter set to ohms, measure the resistance of the oven temperature sensor at room temperature (approximately 75°F). A typical reading should be around 1080 ohms. An open circuit (infinite resistance) indicates a faulty sensor.
5

Inspect the wiring harness and connectors for any signs of damage, corrosion, or loose connections. Repair or replace as needed.
6

If the sensor tests good and the wiring is intact, suspect a faulty oven control board (MCU). Replacing the MCU may be necessary. Note: Ensure the replacement MCU is properly configured for your oven model.
7

Reassemble the oven, reconnect power at the breaker panel, and test oven functionality.

Safety Warning:

Always disconnect power to the appliance at the breaker panel before performing any repairs. Use proper lockout/tagout (LOTO) procedures to prevent accidental power restoration. High voltage is present when the appliance is connected to power.

Prevention:

Regularly inspect the oven temperature sensor and wiring for any signs of damage or corrosion. Avoid using harsh cleaning chemicals inside the oven, as they can damage the sensor. Schedule annual licensed technician appliance inspections.

Expert Tip:

On some Kenmore models, entering service mode (consult your service manual for the correct sequence) allows you to bypass the F3 error and test other oven functions. This is useful for isolating other potential issues.

Frequently Asked Questions

•What is the exact resistance value of a good RTD sensor for my Kenmore oven at 250°F?

The resistance of an RTD sensor increases with temperature. At 250°F, it should be approximately 1400-1500 ohms. Refer to the oven's service manual for the exact resistance chart for your specific model.

•How do I access the oven control board (MCU) on my Kenmore range?

Typically, you'll need to remove the range's back panel or the control panel itself. This often involves removing screws located on the sides, top, or back of the range. Be careful when removing the control panel as it may be connected to the chassis with wires.

•If the sensor is good, and the wiring is good, could the issue be the oven relay board?

Yes, it's possible. While the F3 error primarily points to the sensor circuit, a faulty relay board could interfere with the voltage readings the MCU receives, triggering the error. However, a faulty relay board usually presents other symptoms such as inconsistent heating or clicking noises. Replacing the MCU should be the next troubleshooting step.

Kenmore Oven Error Code F3: Troubleshooting Oven Temperature Sensor Open Circuit

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the exact resistance value of a good RTD sensor for my Kenmore oven at 250°F?

•How do I access the oven control board (MCU) on my Kenmore range?

•If the sensor is good, and the wiring is good, could the issue be the oven relay board?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: