LG · Oven Moderate

CF3 — Right-front cooktop sensor open/short

Right Front surface element sensor circuit is open or shorted. That zone is disabled.

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

How to fix it

  1. Power off at the breaker and lift the cooktop.
  2. Measure RF sensor resistance (~1090 Ω at room temp); replace if open or shorted.
  3. Repair or replace damaged harness sections.
  4. Reseat the cooktop board connector.
  5. Replace the cooktop control board if sensor and wiring test good.

Why it happens

Typical signs: CF3 on display · Right front burner not heating or erratic · Display may go back to normal after CLEAR/OFF until zone is used again

  • Failed RF zone thermistor Sensor element failed open/short.
  • Damaged harness under cooktop Pinch or burn from a hot element.
  • Loose connector at cooktop board Plug not fully seated.
  • Cooktop control board fault Input circuit on PCB 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 cooktop surface 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 CF4 CF4 — Rear Cooktop Sensor Error (Zone Varies by Model) F1 Range F1 — Upper Oven Thermistor Error F10 Range F10 — Door Locking System Failure

All LG codes → All oven codes →

Frequently asked questions

What does the CF3 code mean on a LG oven?

Right Front surface element sensor circuit is open or shorted. That zone is disabled.

What causes the CF3 code on a LG oven?

Failed RF zone thermistor: Sensor element failed open/short. Damaged harness under cooktop: Pinch or burn from a hot element. Loose connector at cooktop board: Plug not fully seated.

Is it safe to keep using a LG oven with a CF3 error?

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

How do I fix CF3 on a LG oven?

Power off at the breaker and lift the cooktop. Measure RF sensor resistance (~1090 Ω at room temp); replace if open or shorted. Repair or replace damaged harness sections.

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.