What F3 / F4 Means
F3 and F4 on a GE wall oven are documented as the oven sensor needing replacement. GE publishes this among its range and wall oven error, fault and function codes for models with electronic oven controls, and asks for a trained technician to diagnose F-codes. The sensor is the probe in the cavity wall that reports temperature; once it reads open, shorted or simply wrong, the control stops rather than heating blind.
Common Causes of F3 / F4
- Failed oven temperature sensor
- Damaged sensor wiring or corroded connector
- Probe bent or dislodged inside the cavity
- Control board input fault
🔧 One Safe Check You Can Try
Let the cavity cool first - overheating and self-clean faults leave the oven and door far hotter than a normal bake. GE's own first step is to switch the oven's circuit breaker off for a minute or two and then restore power. Check the sensor probe inside the cavity has not been bent or pushed out of place by a tray. Beyond that, the sensor's connector is behind the oven, and on a built-in that means the appliance coming out of the cabinet.
⚠ Why You Shouldn't Go Further Than That
- On a built-in wall oven the control and door-lock wiring are reached by unseating the oven from the cabinet - a two-person job with a heavy appliance on a 240 V circuit.
- Sensors are confirmed by resistance measurement, not by appearance - guessing risks replacing a good part.
- Damage caused during a repair attempt may not be covered - check your warranty terms first.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.