An H11 code could point to a breakdown in communication between your Panasonic indoor and outdoor units. These two parts of the system talk to each other constantly over an interconnecting cable, and when that signal drops out, the unit shuts down as a safety measure rather than running blind.
This fault is usually traced to the cable itself, though it can also stem from a fault on either unit’s control board. A brief power interruption partway through a communication cycle can trigger the same code without any lasting hardware problem.
Send us the code and a photo of the display, and a Ford & Doonan technician will get back to you. Please don't reset the unit before you take the photo.
(08) 9331 8800