E05 error and the Amfa4000 display is frozen or unresponsive

Safety first: Disconnect the Amfa4000 from mains power before opening the control housing.

• 1. Power cycle the unit: Unplug or switch off the fused spur for 5 minutes. Restore power and check if the display recovers and E05 clears.
• 2. Inspect for moisture: Remove the control cover and look for signs of condensation, water tracks, or corrosion on the PCB and connectors. If moisture is present, dry gently with a lint-free cloth and allow the unit to air dry fully before reassembly.
• 3. Check ribbon and harness connections: Ensure the keypad/display ribbon cable is fully inserted into the control board connector. Reseat any loose plugs.
• 4. Verify stable power supply: Confirm the Amfa4000 is connected to a properly grounded outlet or spur and that there are no signs of overheating or burning at the plug or wiring.

If the display remains frozen or E05 returns after a power cycle and connector check, the main control PCB or user interface module is likely defective and should be replaced with the correct Amfa4000 control board assembly.