F11 Serious Moderate DIY

LG Oven F11 — Communication error between boards

LG Oven · Error code F11

What F11 Means

The main control board has lost communication with the display/UI board (or the cooktop board on combo ranges) for more than ~10 seconds. Cooking is blocked until the link is restored.

Symptoms

  • F11 or F-11 on display
  • Touch panel unresponsive or partially lit
  • Oven will not start any cycle
  • Buttons may beep but nothing happens

Common Causes

1
Loose ribbon or communication harness between boards

Connector backed off during heat cycling or shipping/install.

2
Failed display/UI board

UI MCU not transmitting on the bus.

3
Failed main control board

Main PCB cannot receive.

4
Voltage brownout or noisy power

Marginal incoming voltage corrupts the bus.

How to Fix It

  1. Power the oven off at the breaker for 60 seconds and restart.
  2. If F11 returns, disconnect power and pull the back panel.
  3. Reseat every connector on the main control board and the display board, especially the communication ribbon.
  4. Inspect harnesses for crushed pins or melted insulation near the cavity.
  5. Confirm 120 V at the line input to the main board is steady.
  6. If reseating does not clear it, swap the display board first (more common failure), then the main board.

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 oven display/UI board View on Amazon→ Common replacement LG range main control board 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 CF3 CF3 — Right-front cooktop sensor open/short CF4 CF4 — Right-rear cooktop sensor open/short F1 Range F1 — Upper Oven Thermistor Error

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.