Frigidaire Range F31 Error Code — What It Means
The F31 error code on a Frigidaire range signals an open or unreadable oven temperature sensor (RTD) circuit. The electronic control board has lost the ability to receive a valid temperature signal from the sensor probe, so it stops normal oven operation to prevent unsafe heating. The fault means the sensor circuit is out of the expected range, either showing an open circuit, a short to ground, or resistance far from the normal value.
In most cases the oven temperature sensor itself has failed. The control board expects to see around 1,080 ohms of resistance at room temperature from a healthy sensor. When the sensor element degrades, resistance drifts out of range or the probe wire breaks internally, triggering F31. Loose or corroded harness connectors between the sensor and the control board are the second most common cause. A short to the cabinet frame in the sensor wiring or a failed control board are less frequent but still possible.
Before You Replace Anything
Many people replace the electronic control board first because the code sounds electronic. Always test the sensor resistance (should be about 1,080 Ω at room temperature) and check the harness connectors before buying a control board.
Common Causes
- Failed oven temperature sensor (~60%) The RTD probe element degrades over time and reads out of range or open, so the control board throws F31.
- Loose or corroded sensor harness connector (~20%) The plug between the sensor wire and the control board oxidizes or backs out, creating an intermittent open circuit.
- Sensor wire shorted to cabinet ground (~10%) Insulation on the sensor wire rubs through where it passes a sharp edge, grounding one lead and pulling the reading out of range.
- Damaged sensor wiring harness (~5%) A wire breaks inside the insulation between the sensor and the control board, opening the circuit.
- Failed electronic control board (~5%) The sensor input circuit on the control board itself fails even though the sensor and wiring are good.
Quick Diagnosis
Answer these to narrow it down fast.
Does the F31 code clear for a few minutes after you power-cycle the range, then return when the oven heats?
No: The fault is persistent. Proceed to measure the sensor resistance to confirm whether the sensor itself has failed.
With power off and the sensor unplugged, does the sensor measure about 1,080 Ω across its two leads at room temperature?
No: The sensor is out of specification. Replace the oven temperature sensor probe.
After replacing the sensor, does the F31 code stay away and the oven heat normally?
No: Recheck all harness connections. If the wiring and new sensor both test good, the control board sensor input circuit has likely failed and the board needs replacement.
Step-by-Step Fix
- Turn off power at the circuit breaker or unplug the range to prevent shock while you work on the sensor circuit.
- Remove the rear panel or oven back to access the oven temperature sensor, which is a metal probe threaded into the oven cavity wall with a wire harness plug behind it.
- Disconnect the sensor harness plug at the sensor or at the control board, depending on your model’s layout.
- Measure sensor resistance across the two sensor leads with a multimeter set to ohms. A good sensor reads about 1,080 Ω at room temperature.
- Check for shorts to ground by measuring from each sensor lead to the metal cabinet frame. Both readings should be open (infinite resistance). Zero ohms means a wire is shorted.
- Replace the oven temperature sensor if resistance is far from 1,080 Ω or if either lead is shorted to ground. Unscrew the old probe, install the new one, and reconnect the harness.
- Restore power and test the oven through a bake cycle. If F31 returns and the new sensor tests good, inspect harness connectors for damage or replace the electronic control board.
Parts Often Needed
| Part | Notes |
|---|---|
| Frigidaire oven temperature sensor (RTD probe) | Amazon | Match your range model number. Most are 1,080 Ω at room temperature and thread into the rear oven wall. |
| Frigidaire range electronic control board | Amazon | Only if sensor and wiring both test good but the code persists. Verify your model and board part number before ordering. |
When to Call a Pro
Call a technician if you are uncomfortable working behind live 240-volt range circuits, if the sensor and wiring both test good but the code remains (pointing to a control board failure), or if repeated sensor replacements do not solve the problem. A qualified appliance tech has the meters and wiring diagrams to trace intermittent harness faults and can confirm control board failure before you invest in an expensive part. If your range is still under warranty or you need the oven repaired quickly for daily cooking, professional service is the faster path.
Rough cost: DIY runs about $20-50 for a sensor, 20-40 min. A pro service call runs about $150-250 service call including sensor.