LG · Oven Moderate

CF4 — Rear Cooktop Sensor Error (Zone Varies by Model)

CF4 means a cooktop surface-temperature sensor circuit is open or shorted, and the control disables that zone. Which zone depends on your model: LG documents CF4 as the Right Rear sensor on some ranges, but on LSIL6332-series induction ranges LG's service manual maps CF4 to the Center Rear sensor (with CF5–CF8 covering the other induction zones). Check your model's manual before assuming which burner is affected.

Keep using it?
Yes, with caution
DIY difficulty
Moderate

How to fix it

  1. Check your model's manual or service sheet to confirm which rear zone CF4 refers to (Right Rear on most ranges; Center Rear on LSIL6332-series induction ranges) before replacing anything.
  2. Disconnect power.
  3. Lift the cooktop, unplug the sensor for the affected zone, and measure its resistance against your model's spec.
  4. Replace the sensor if open or shorted.
  5. Inspect and repair the harness; reseat the connector at the cooktop board.
  6. If the sensor and wiring test good, replace the cooktop control board.

Why it happens

Typical signs: CF4 on display · One rear cooktop zone (Right Rear on most ranges, Center Rear on LSIL6332-series induction ranges) is cold or runs uncontrolled · Other zones may keep working normally

  • Failed zone thermistor The surface sensor for the affected rear zone is open or shorted.
  • Harness damage under the cooktop Chafing against the chassis or heat from a neighboring element.
  • Loose cooktop board connector The sensor plug isn't fully seated at the cooktop board.
  • Cooktop control board fault The input circuit for that zone has 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 CF3 CF3 — Right-front cooktop sensor open/short 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 CF4 code mean on a LG oven?

CF4 means a cooktop surface-temperature sensor circuit is open or shorted, and the control disables that zone. Which zone depends on your model: LG documents CF4 as the Right Rear sensor on some ranges, but on LSIL6332-series induction ranges LG's service manual maps CF4 to the Center Rear sensor (with CF5–CF8 covering the other induction zones). Check your model's manual before assuming which burner is affected.

What causes the CF4 code on a LG oven?

Failed zone thermistor: The surface sensor for the affected rear zone is open or shorted. Harness damage under the cooktop: Chafing against the chassis or heat from a neighboring element. Loose cooktop board connector: The sensor plug isn't fully seated at the cooktop board.

Is it safe to keep using a LG oven with a CF4 error?

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

How do I fix CF4 on a LG oven?

Check your model's manual or service sheet to confirm which rear zone CF4 refers to (Right Rear on most ranges; Center Rear on LSIL6332-series induction ranges) before replacing anything. Disconnect power. Lift the cooktop, unplug the sensor for the affected zone, and measure its resistance against your model's spec.

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