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