Guardian opener LED shows code “15”, light will not turn on/off correctly or flickers, door operation normal.

Safety first: Turn off power and allow bulbs to cool before handling. Use only bulbs within the wattage rating specified by Guardian.

• Use correct bulbs: Replace existing bulbs with garage-door-opener-rated LED or incandescent bulbs of the correct wattage. Avoid CFLs and non-rated LEDs.
• Inspect socket: Check the lamp socket for corrosion or burned contacts. Clean gently or replace the socket if damaged.
• Tighten bulb: Ensure the bulb is screwed in firmly but not overtightened.
• Test without bulb: Remove the bulb and run the opener. If the error clears, the bulb type may have been causing issues.
• Replace logic board: If the light still flickers or will not respond with a known-good bulb and socket, the light control circuit on the Guardian logic board is likely faulty and the board should be replaced.