Vokera Vibe fault codes

15 codes from the Vokera manual for the Vibe gas boiler. Pick one for what it means, the likely causes and where to start.

Code	What it means
A10	Flame lockout / condensate drain obstructed / flue gas exhaust/air suction obstructed
A30	Fan fault
A40	Fill the system
A41	Fill the system (transitional)
A59	High power supply voltage
A60	DHW probe fault
A70	Flow sensor fault / flow sensor overtemperature / flow/return sensor differential
A80	Return probe fault / return probe overtemperature / return-flow sensor differential
A90	Flue gas probe fault
A91	Reset operating hours counter (related to fault A91)
AF1	Heating anti-freeze protection active
AF2	DHW anti-freeze protection active
CFS	Service call signal / periodic boiler control
E091	Heat exchanger cleaning required (unusual usage threshold)
SFS	STOP FOR SERVICE (permanent inhibition)