Introduction
The F2 or F20 code indicates an overheat or runaway heat condition in the oven. In normal cook mode, it indicates that the control senses a temperature of over 650°F(343°C) in the oven. In self-clean mode, it indicates a temperature of over 915°F (491°C). We will look at the potential causes below.
There are three main possibilities: The oven temperature sensor is bad, the wiring harness between the sensor and the Electronic Range (or oven) Control (ERC) is defective, or the ERC has failed.
A multimeter is an important tool in troubleshooting these devices, so knowing how to use one is pretty important.
Here is a link to GE Oven Parts if you find a defective part.
The Basics
Disconnect Power
As with almost any error code, resetting the device is a good first step. For GE ovens, the easiest way to do this is to disconnect the power.
- You may be able to reach the plug on gas or electric ranges or stoves. You can disconnect the power at the circuit breaker if it is difficult to reach.
- Built-in ovens (like wall ovens) require you to disconnect power at the circuit breaker since they are usually hardwired and don't have a plug.
- Leave the power disconnected for 5 minutes.
- Reconnect the power and check to see if the error returns.
- If it does, move on to the next item. If not, monitor the oven, as this type of error often starts with occasional error codes, which power cycling clears and then grows in frequency.
Causes
Get a multimeter and measure the sensor resistance. At room temperature, it should be about 1100 Ω. For more details, see More About Oven Temperature Sensors.
- Shut off power to the unit before checking this resistance
- Disconnect the sensor so you can measure it directly.
- You might encounter a sensor with an abnormally high resistance, like 1600Ω, which will lead to overtemperature errors.
- Replace the sensor if it reads more than 1150Ω or less than 1050Ω.
When checking the sensor's resistance, check for continuity between each sensor lead and the sensor's shell or mounting plate.
- There should be no continuity; if there is, replace the sensor.
- If the sensor checks out, reconnect it, then move to the next step.
If the sensor is giving correct resistance values at room temperature, then the next step is to check if what the control board is "seeing" is correct. Because the resistance changes are relatively small, a bad connector or crimp can add enough resistance to cause an error message.
The control board sees a higher resistance as a higher temperature. So, a corroded, oxidized or loose connection could add to the total resistance and make it high enough to read as an overtemperature condition.
- You will want to trace the wire from the sensor to the connectors on the control board and then use your meter to check the resistance in the circuit at the control board.
- As you trace the wire, make sure it is in good condition. If you find any melted insulation or pinched wires, repair them. Make sure you use wire with insulation that matches what you found and porcelain or ceramic wire nuts.
- Disconnect the connectors for the temperature sensor wires at the control board and check the resistance.
- Check the connectors on the control board for corrosion. They should be very clean.
- Check any other connectors or splices in the circuit for any corrosion or burns.
- Some have been known to fail over time, so unplug them and check them. If they have failed, you may have to substitute porcelain or ceramic wire nuts for them.
The special plastic connectors supplied with the sensor will often fail over time. Also, the porcelain wire nuts used instead of the plastic connectors can occasionally be a problem. Reinstall them to make sure the connection is tight. You might even want to re-strip the wire to have a fresh portion for the connection.
If the values check out, go to the next step.
At this point, the only thing to replace is the ERC. They can see a fair amount of heat, and some have to be cooled by the fan that draws air across them. Another sign of an ERC problem is the F2 error showing while the oven is not on (also known as in clock mode).
Frequently, you may have a real overtemperature condition because relay contacts on the control board will weld, and the board is unable to shut off a heating element. Either Broil or Bake can be affected. Since the control board is often difficult to obtain or costly, we check it last.
If the above steps point to a defective control, then power down the unit, and replace the ERC. Be prepared to run through a setup process for the unit.
More About Oven Temperature Sensors
The oven temperature sensor is what is called a resistive temperature device or RTD. They use a coiled length of platinum wire which changes in resistance with temperature. Unlike a thermistor, the resistance of an RTD changes essentially linearly with temperature, with a resistance increase of approximately 2Ω/°F
- In some instances the sensor can fail by losing its linear character. You should, if possible, check the sensor at another temperature to see if it is acting as it should. Since these sensors are essentially identical from oven to oven, you can check them at other temperatures for correct values.
- For higher temperatures, you may be able to use a toaster oven or an electric hot plate. A digital kitchen thermometer can be used to verify the sensor's actual temperature or an infrared thermometer can be used.
- 32°F (0°C) — 1000Ω
- 77°F (25°C) — 1100Ω
- 250°F (121°C) — 1450Ω
- 350°F (177°C) — 1650Ω
Related Problems
14 common problems
View all