LG · Oven Serious

F20 — Lower oven door lock failure

The lower-oven door lock motor failed to drive the latch to the commanded position (locked or unlocked) within the timeout. Self-clean and sometimes baking are blocked until cleared.

Keep using it?
Limited use only
DIY difficulty
Moderate
Verified against
lgparts.com ↗

How to fix it

  1. Cool the oven fully — DO NOT force a hot self-clean door.
  2. Power down at the breaker for 60 seconds and retry.
  3. If still locked, pull the breaker, remove the top panel, and access the lower door lock assembly.
  4. Manually move the latch cam to the unlocked position with the motor unpowered.
  5. Test lock motor winding resistance and switch continuity in both positions.
  6. Replace the lock assembly if the motor is open or the switches are stuck.
  7. If the lock and switches check good, the main control board is the next suspect.

Why it happens

Typical signs: F20 or F-20 on display · Lower door will not lock for self-clean, or will not unlock after self-clean · Audible clicking from latch motor with no movement · Door physically stuck closed

  • Failed lower door lock motor Motor windings open or gearbox stripped.
  • Broken/misadjusted lock-position switch Control never sees the locked-state signal.
  • Latch mechanically bound Warped door or debris stops the cam.
  • Harness or control board fault driving the lock Voltage to the lock motor missing.

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 door lock assembly 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: lgparts.com.