CF3 Moderate Moderate DIY

LG Oven CF3 — Right-front cooktop sensor open/short

LG Oven · Error code CF3

What CF3 Means

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

Symptoms

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

Common Causes

1
Failed RF zone thermistor

Sensor element failed open/short.

2
Damaged harness under cooktop

Pinch or burn from a hot element.

3
Loose connector at cooktop board

Plug not fully seated.

4
Cooktop control board fault

Input circuit on PCB failed.

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.

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.

Common replacement LG cooktop surface sensor View on 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 — Right-rear cooktop sensor open/short F1 Range F1 — Upper Oven Thermistor Error F10 Range F10 — Door Locking System Failure

All LG codes → All oven codes →

Verified against manufacturer documentation: lg.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.