Cause of error code Er:78

Cascade Communication Error

Solution for error code Er:78

NOTE: This error will only appear in a cascaded system.

- Turn power OFF and ON at the appliance display panel.

- If error reappears, ensure all cascaded appliances are powered ON.

- If error reappears, check Installer Mode parameter 13 at the Master appliance. Ensure the number of cascaded units chosen in this parameter matches the number of cascaded units in the system.

- If error reappears, check Installer Mode parameter 10 at all cascaded appliances. Ensure the address number matches that of the connected appliance (01 for Master, 02 for Follower 1, etc.) and that no numbers are skipped or repeated.

- Ensure every unit in the cascade system is connected properly. Inspect the cascade cables and ensure all are connected without damage or defect. Repair or replace any damaged cables.

-. If the problem persists, replace the main control.