LG · Oven Minor

F18 — Second meat probe error

On models with two probe inputs (or a second cavity), the secondary probe circuit is open or shorted. Probe cooking on that cavity is disabled.

Keep using it?
Yes — fix when convenient
DIY difficulty
Easy
Verified against
lgparts.com ↗

How to fix it

  1. Unplug both probes and press CLEAR/OFF.
  2. Test with a known-good OEM probe in the second jack.
  3. Inspect the jack for grease, debris, or bent pins.
  4. If F18 persists with no probe inserted, the receptacle/harness is faulty — replace it.
  5. Replace the probe itself if a known-good probe in the same jack works.

Why it happens

Typical signs: F18 or F-18 on display · Probe cook on the second cavity will not start · Probe icon flashing for the second oven · Standard bake still works

  • Damaged secondary probe cable Tip element or pigtail open from repeated bending.
  • Contaminated cavity-wall jack Grease in the second jack.
  • Probe wrong type for the jack Aftermarket probe with wrong resistance curve.
  • Open wiring or failed jack on the cavity wall Harness from jack to board opened.

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 meat probe (OEM) 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.