Oven High Severity
F1 Appliance Error Code

LG Oven F1 Error: Oven sensor open

LG oven error — here’s what you need to know. The F1 error code on your LG oven indicates upper oven temperature sensor open circuit. This is a High severity issue. What Does F1 Mean on an LG Oven? The F1 error code means the control board cannot detect a valid signal from the upper […]

~65%

DIY Fixable

From 5

Typical Repair Cost

30–60 min

Pro Repair Time

Quick Assessment

Answer to continue safely

Is it safe to keep using?

No. Do not use the oven with an F1 fault active. Without a working temperature sensor, the oven cannot regulate heat and may overheat if the control board is also malfunctioning.

Can I reset the code?

Yes. A power cycle can temporarily clear F1, but the code will return as soon as the oven attempts to read the sensor again. The underlying fault must be repaired.

When to stop immediately?

Stop if you notice: Stop if you notice any burning smell from inside the oven cavity or behind the control panel., Stop if the wiring harness shows signs of heat damage or melted insulation..

Symptoms You May Notice

Oven cavity does not heat up

The bake and broil elements remain cold because the control board cannot confirm oven temperature and has locked out the heating circuits.

F1 code displayed with alert beeping

The oven control displays F1 continuously and beeps; the code typically reappears within moments of being cleared if the sensor fault persists.

All oven cooking modes are unavailable

Bake, broil, convection bake, and convection roast cannot be started; only the oven clock and timer may still function.

Inconsistent temperature performance

The oven runs too hot, too cold, or cycles erratically because the control board receives inaccurate temperature readings from the faulty sensor.

Possible Causes

1

Failed oven temperature sensor (RTD probe)

The resistance-temperature detector inside the oven cavity has broken internally, producing an open circuit that the board reads as an out-of-range sensor.

DIY Possible
2

Broken sensor wiring harness

A wire in the harness between the sensor and the control board has cracked or pulled free from its connector, interrupting the signal path.

DIY Possible
3

Faulty oven control board

The oven control board's sensor input circuit has failed, displaying F1 even when the sensor and wiring test within specification.

Requires Professional

Safe Checks You Can Do

These checks are safe for homeowners. No disassembly required. Do not remove panels or access internal components.
  1. 1

    Hard reset the oven

    Turn off the oven's circuit breaker for 60 seconds, then restore power. If F1 was caused by a transient voltage spike, this may clear it permanently.

  2. 2

    Locate and inspect the oven sensor

    With the oven unpowered, look inside the upper oven cavity for the sensor probe (a thin metal rod mounted at the upper rear wall). Confirm it is not cracked, bent, or touching the oven wall.

  3. 3

    Measure sensor resistance

    Disconnect the sensor harness connector at the rear of the oven and measure resistance across the two sensor leads. A healthy LG oven sensor reads approximately 1,080–1,090 ohms at room temperature. An OL (open) reading confirms sensor failure.

When to Call a Professional

Contact a qualified technician if:

  • F1 persists after installing a confirmed-good replacement sensor.
  • Wiring damage is found in the oven cavity or behind the control panel.
  • Oven control board replacement is required.

Need Professional Help?

Find qualified technicians in your area for proper diagnostics and repair.

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