Frigidaire error code F31: The oven temperature sensor is reading abnormally low resistance (shorted). The board interprets this as the oven being extremely cold and applies continuous heat — a safety-critical condition.
The oven temperature sensor is reading abnormally low resistance (shorted). The board interprets this as the oven being extremely cold and applies continuous heat — a safety-critical condition.
Do not attempt to turn off the oven with the control panel. If the oven is overheating, go directly to the electrical panel and shut off the circuit breaker. Leave the oven door closed.
Wait at least 1 hour after the breaker is off before touching anything inside the oven or at the back of the range. Internal components can reach 600°F during a runaway heating event.
At room temp, the sensor should read ~1,080–1,100 Ω. A very low reading (shorted sensor, e.g., <100 Ω) tells the control board the oven is cold, causing it to keep heating. This is the most common cause of oven overheating.
Tools needed: Multimeter, Screwdriver set
If the sensor tests good, the relay on the electronic oven control board that switches the bake or broil element may be welded shut (stuck closed). This causes continuous heating even when the oven is turned off. With power off, inspect the relay for visible burn damage.
Tools needed: Screwdriver set
Replace either the temperature sensor (if shorted) or the control board (if the relay is stuck). After replacement, set the oven to 350°F and monitor the temperature with an oven thermometer. Confirm it stabilizes within ±25°F of set.
Tools needed: Oven thermometer, Screwdriver set
Turn off the circuit breaker immediately. Test the RTD sensor resistance — a shorted probe reads much below 1,000 Ω. Replace the sensor and re-route wiring away from heating elements.