Technical description
Without solar control unit
What causes this fault?
This fault occurs when the boiler's internal computer is incorrectly programmed to look for a solar thermal system that isn't actually there. It usually happens after a software update or a component replacement where the 'coding' hasn't been set correctly to match your home's specific setup. Essentially, the boiler is waiting for data from a solar control module that doesn't exist, leading to a communication error.
DIY fix possible
Locate the 'OK' and 'Menu' buttons (or the touchscreen menu).Navigate to the 'Service' or 'Settings' sub-menu.Restart the boiler using the main power switch to see if it clears the communication error.