Display shows code 15, opener operates but light does not turn on or off correctly.

Safety first: Turn off power before changing bulbs or touching the lamp holder.

• Check bulb type: Merlin openers typically require a specific maximum wattage and may specify incandescent or approved LED types. Install a bulb within the rated wattage.
• Inspect bulb and holder: Remove the bulb and check for broken filaments or darkened glass. Clean the lamp holder contacts with a dry cloth and ensure the center contact is not bent flat.
• Test with known‑good bulb: Install a new, correct‑type bulb and test operation. If the light still fails, the relay or PCB may be faulty.
• Board inspection: With power off and cover removed, look for a small relay near the light terminals. Burn marks or cracking indicate failure; the board should be replaced.