LG F9

LG Oven Error F9: Upper Oven Not Heating — No Temperature Rise

Clear meaning, realistic next steps, and safe guidance without turning the page into a long repair manual.

What it means

The upper oven is not heating at all — the control board is not detecting any temperature rise from the bake element during a bake cycle. The oven is completely cold during operation.

Severity

High - stop using the LG oven until the cause is understood or professional help is arranged.

Can you fix it yourself?

Partial — start with DIY steps

Most likely cause

Bake element burned out — the most common cause of no-heat faults on electric ovens

Estimated time for safe first checks: 20–40 min for element test and replacement; Professional if board fails.

Step-by-Step DIY Fix Guide

  1. SAFETY: Disconnect power at the circuit breaker.
  2. Visually inspect the bake element at the bottom of the oven — look for a break, blister, or burn mark along the element wire.
  3. If the element looks intact, test with a multimeter set to ohms — a good element reads 15–30 ohms. An open circuit (infinite ohms) means the element has failed.
  4. Replace the bake element if it tests open circuit (see F6 steps for replacement process).
  5. If the element tests good, check the oven temperature sensor (see F1 steps).
  6. If both test good, call a technician to inspect the thermal fuse and control board relay.

If the warning comes back after restart

  • If the warning returns immediately after a clean restart, the sensor or wiring path becomes more likely than a one-time glitch.
  • F9 persists after the bake element tests good and the temperature sensor is within specification

What This Error Means

Error F9 on your LG oven means: The upper oven is not heating at all — the control board is not detecting any temperature rise from the bake element during a bake cycle. The oven is completely cold during operation. The range's self-diagnostic system has detected this condition.

The most frequent cause is bake element burned out — the most common cause of no-heat faults on electric ovens. Work through the causes and fix steps below in order — many LG oven errors are resolved without a service call.

Many cases of F9 can be resolved by the homeowner. The steps below cover the full DIY checks — if they do not resolve the error, a technician is needed.

Oven temperature sensor faults are among the most common LG oven errors. The sensor is a simple probe on the back wall of the oven cavity — reconnecting a loose harness connector resolves around half of all sensor fault codes. Sensor replacement is a 15-minute DIY repair when the connector check does not resolve it.

Most Likely Cause by Symptom

The LG oven may stop, pause, or refuse to complete the cycle normally.

Likely cause: Bake element burned out — the most common cause of no-heat faults on electric ovens

Check first: SAFETY: Disconnect power at the circuit breaker.

The warning may return immediately because the appliance is detecting an internal fault.

Likely cause: Bake element relay failure on the control board — the relay is not closing when the board commands heat

Check first: Visually inspect the bake element at the bottom of the oven — look for a break, blister, or burn mark along the element wire.

Common Causes

  • Bake element burned out — the most common cause of no-heat faults on electric ovens
  • Bake element relay failure on the control board — the relay is not closing when the board commands heat
  • Thermal fuse blown — a safety fuse in the oven wiring has tripped due to an overtemperature event
  • Oven temperature sensor failure causing the board to believe the oven is already at temperature

What Not to Do

  • Do not bypass or short-circuit the thermal fuse to test the oven — the fuse exists to prevent a fire and must be replaced, not bypassed

Model and Display Variation Notes

Model-family notes

  • LG oven display wording and code formats can vary by series.
  • If your model behaves differently, check the owner manual before trying any deeper maintenance step.

Display and panel differences

  • Panel wording can vary by series, so confirm the exact code pattern before buying parts.

Parts, Tools and Service Options

Service option

LG service visit if the warning returns after the basic checks are complete.

Manual and model check

Check your exact model and manual before ordering any LG oven parts.

Common parts

  • Bake element if element has failed ($20–$60)
  • Thermal fuse if fuse has blown ($5–$20)
  • Main control board if relay has failed ($100–$250)

This section stays service-first because the page points more strongly toward support or professional repair than a routine parts purchase.

When Not to Keep Troubleshooting

F9 persists after the bake element tests good and the temperature sensor is within specification

How to Prevent It Recurring

  • Avoid placing bakeware directly on the oven floor — this blocks heat circulation and can overheat the bake element

Related Error Codes

Extra notes

  • This page is based on LG support material and stays conservative where model-specific guidance may vary.
  • The goal is to help you identify safe first checks before you move into parts, service, or model-specific manual lookup.

Source and model notes

Last reviewed: 2026-04-08

Based on: Based on LG support material and edited into consumer-safe guidance for the exact code family on this page.

View LG US Official Support

Model coverage note: LG oven code meanings can vary by series, control panel, and model family, so use this page as a safe starting point rather than a replacement for the model-specific manual.

Important: FixThisError is an independent guide, not the manufacturer. Use your model-specific manual when the panel wording or behavior differs.

Always disconnect power before inspecting appliances. If unsure, contact a licensed appliance technician.