Gliderol opener shows E4 and refuses to close the door; door may open normally but will not close from remote or wall button.

Safety first: Work from a stable ladder and keep clear of the moving door. Do not bypass safety beams permanently; they are a critical safety device.

Steps to fix safety beam fault:

• 1. Check beam indicators: On Gliderol safety beams, look for LED indicators on the sender and receiver. A solid light usually indicates alignment; flashing or off indicates a fault.
• 2. Clean lenses: Use a soft cloth and mild cleaner to wipe dust, cobwebs, and moisture from the beam lenses.
• 3. Realign beams: Loosen the mounting screws slightly and adjust the receiver so it points directly at the transmitter. Tighten screws while keeping alignment. The LED should turn solid when aligned.
• 4. Inspect wiring: Trace the low-voltage cables from the beams back to the Gliderol control board. Look for staples through the cable, cuts, or corrosion at terminals. Re-terminate any loose wires and ensure polarity matches the wiring diagram.
• 5. Test operation: With beams aligned and LEDs solid, try closing the door. Wave an object through the beam; the door should stop or reverse.

If one beam LED never lights even with correct wiring, that beam unit is likely faulty and should be replaced with a compatible Gliderol safety beam kit.