Incorrect Function - Chaffoteaux & Maury Britony Combi SE 80 Installation And User Instructions Manual

Incorrects functions is signalled by leds (rep 22) display flashing correspond with chart below.
CODE
30 40 50 60 70
H H H H H H H H H H
H H H H H H H H G G
H H H H H H H H G G
H H H H H H G G H H
H H H H H H G G H H
H H H H H H G G G G
H H H H G G H H H H
H H H H G G H H G G
H H H H G G H H G G
H H H H G G G G H H
H H G G H H H H H H
H H G G H H G G H H
H H G G H H G G G G

INCORRECT FUNCTION

FAULT
80
G G
Overheat sensor switch open.
H H
Overheating defect without lock out.
G G
No flame detection.
H H
Ionisation printed circuit board faulty.
G G
Antifrost mode on (pump in operation).
H H
Antifrost mode on (burner and pump in operation).
G G
Domestic hot water thermistor faulty (open circuit).
H H
Domestic hot water thermistor faulty (short circuit).
G G
Central heating thermistor flow faulty (open circuit).
H H
Central heating thermistor flow faulty (short circuit).
G G
Low water pressure in the Central Heating circuit.
G G
Fan on but does not activate air pressure switch.
H H
Fan off but air pressure switch fails to return to off position.
10