A.O. Smith HW 300 Instruction Manual page 29

START
STAGE 1
TRIAL FOR
IGNITION
STAGE 2
MAIN BURNER
OPERATION
END
THERMOSTAT (CONTROLLER) CALLS FOR HEAT
SPARK GENERATOR POWERED
First valve (pilot) operator opens
PILOT BURNER OPERATION
Pilot burner lights.
Module senses
flame current.
FLAME CURRENT SENSED
• Spark generator off.
• Second valve operator (main) opens.
MAIN BURNER OPERATION
Module monitors pilot flame current.
THERMOSTAT (CONTROLLER) SATISFIED
Valves close, pilot and main burners are off.
Pilot burner does not light
Module Response
S-8600M After 15 sec. ignition
shut-down. 5 minute
time delay before re-try.
S-8600H After 15 sec. ignition
system locks out
must be manually reset.
29
POWER INTERRUPTION
System shuts off, restarts
when power is restored.
PILOT FLAME FAILURE
Main valve closes.
Module starts trial for
ignition.