LG · Oven Moderate

F4 — LG Range F4 — Lower Oven Thermistor Error

F4 means the lower oven temperature sensor (thermistor) is reading out of range (double-oven models).

Keep using it?
Yes, with caution
DIY difficulty
Moderate
Verified against
lg.com ↗

How to fix it

  1. Reset at the breaker for 30 seconds.
  2. Test the lower oven sensor resistance and check wiring; replace if out of spec.

Why it happens

Typical signs: Lower oven heats incorrectly · F4 on the display

  • Failed lower thermistor The lower oven temperature sensor has failed.
  • Sensor wiring fault A damaged lower sensor harness.

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 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 — Rear Cooktop Sensor Error (Zone Varies by Model) F1 Range F1 — Upper Oven Thermistor Error

All LG codes → All oven codes →

Frequently asked questions

What does the F4 code mean on a LG oven?

F4 means the lower oven temperature sensor (thermistor) is reading out of range (double-oven models).

What causes the F4 code on a LG oven?

Failed lower thermistor: The lower oven temperature sensor has failed. Sensor wiring fault: A damaged lower sensor harness.

Is it safe to keep using a LG oven with a F4 error?

Yes, with caution. This is rated a moderate-severity fault.

How do I fix F4 on a LG oven?

Reset at the breaker for 30 seconds. Test the lower oven sensor resistance and check wiring; replace if out of spec.

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.