NORMAL IGNITION SEQUENCE - TIMINGS NOMINAL
THERMOSTAT DEMAND
COMBUSTION AIR BLOWER
GAS VALVE
IGNITION SPARK
BLOWER
IGNITION TRIAL
011004030SDNOCES
ON / CLOSED
OFF / OPEN
END OF
DEMAND
1
COMBUSTION AIR PROVE SWITCH
5 45
FIGURE 19
RETRIALS - IGNITION ATTEMPT SEQUENCE - TIMINGS NOMINAL
THERMOSTAT DEMAND
COMBUSTION AIR BLOWER
GAS VALVE
IGNITION SPARK
BLOWER
IGNITION TRIAL
SECONDS0 30 40 75
ON
OFF
65 100 110
WATCHGUARD
LOCKOUT
COMBUSTION AIR PROVE SWITCH
5
FIGURE 20
THERMOSTAT DEMAND
COMBUSTION AIR BLOWER
GAS VALVE
IGNITION SPARK
BLOWER
IGNITION TRIAL
SECONDS0 30
ON
OFF
IGNITION CONTROL TIMING
30
30
HEATING
CYCLE
END OF
THERMOSTAT
DEMAND
123
42 SEC. 122 SEC.
FIGURE 21
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