Ariston microCombi Servicing Instructions page 21

IS THE
AIR PRESSURE SWITCH
ACTIVATED?
YES
DOES
THE SPARK
SEQUENCE
START?
YES
IS THE BURNER
ALIGHT?
YES
HAS THE
BOILER SAFETY
SHUTDOWN BEEN
ACTIVATED?
NO
Supplied By www.heating spares.co Tel. 0161 620 6677
NO
CHECK
∆P ON AIR
PRESSURE TEST
POINT
∆ ≤
P 0.55mbar
POWER
NO
TO SPARK
GENERATOR?
YES
POWER TO
NO
GAS VALVE?
YES
YES
∆ P ≥0.55mbar
1 - Check/replace A.P. switch
1 - Check exhaust/air intake
2 - Check venturi & tubes
3 - Check fan efficiency/replace
1 - Check/replace cable
2 - Check/replace P.C.B.
NO
1 - Check/replace spark
generator
2 - Check/replace ignition
electrodes and cables
3 - Check spark gap
1 - Check/replace cable
2 - Check/replace P.C.B.
NO
1 - Check gas supply pressures
2 - Check gas pressure to
burner
3 - Check spark gap
4 - Check/replace gas valve
1 - Check if flame strikes
detection electrode
2 - Check soft-light gas
pressure
3 - Check/replace detection
electrode
4 - Check/replace P.C.B.
21