terminals 4&5 at X3 on the boiler to 1&3 at the hive (doesnt matter which way round), and L to L and N to N, that is the wiring for 240v switching , remember when you turn the power back on to the boiler it will not come on for 7 minutes and will keep showing a code think is C1 05 , this happens every time the power is turned off or the system pressure drops, you just have to wait till it runs through all its tests before the boiler will come on, it is just how it works you havent done anything wrong