LG · Oven Critical

F2 — Upper oven over-temperature / thermistor short

The upper oven temperature sensor (thermistor) circuit reads short or the oven is registering a temperature far above any cooking setpoint. The control treats this as a runaway-heat condition and locks out cooking.

Keep using it?
No — service first
DIY difficulty
Moderate
Verified against
lg.com ↗

How to fix it

  1. Press CLEAR/OFF, then power the oven down at the breaker for 60 seconds.
  2. If F2 returns on restart and the cavity is hot, leave the breaker OFF — do not keep cycling power.
  3. Unplug or kill the breaker, pull the rear panel, and unplug the oven temperature sensor at the connector.
  4. Measure sensor resistance at room temperature; it should read about 1080–1100 Ω. Short or open = replace the sensor.
  5. Inspect the sensor harness for melted insulation or pinch points against the cavity wrap.
  6. If the sensor and harness are good and F2 returns, the bake relay on the main control board is the next suspect — service the main PCB.

Why it happens

Typical signs: F2 or F-2 on display · Oven shuts down mid-cook · Element may have been running at full power before fault · Will not start a new bake cycle

  • Shorted oven temperature sensor (thermistor) Sensor reads near 0 Ω instead of ~1080 Ω at room temp, telling the board the oven is freezing so it never cuts the element.
  • Pinched or chafed sensor harness Wires touching the cavity wall short the signal pair to ground.
  • Welded bake-relay contacts on main PCB Relay stays closed, the element will not shut off, and the sensor finally reports the overheat.
  • Failed main control board Logic that opens the relay or reads the sensor has failed.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • LG oven temperature sensor (thermistor) Common replacement
    Amazon →
  • LG range main control board Common replacement
    Amazon →

More LG oven codes

5b 5b — Sabbath Mode active (not a fault) CF1 CF1 — Left-front cooktop sensor open/short CF2 CF2 — Left-rear cooktop sensor open/short CF3 CF3 — Right-front cooktop sensor open/short CF4 CF4 — Right-rear cooktop sensor open/short F1 Range F1 — Upper Oven Thermistor Error

All LG codes → All oven codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: lg.com.