Lennox LGA Series Unit Information page 24

burners do not ignite, the ignition control will attempt to ignite
the burners up to two more times. If ignition cannot be obtained
after the third attempt, the control will lock out. The ignition con-
trol is not adjustable.
The Johnson control is illustrated in figure 14. The four
spade connections are used to connect the control to unit.
Each of the four spade terminals are identified by function.
The spark electrode wire connects to the spark-plug-type
connector on top of the control.
ON / CLOSED
OFF / OPEN
THERMOSTAT DEMAND
COMBUSTION AIR BLOWER
COMBUSTION AIR PROVE SWITCH
IGNITION SPARK
IGNITION TRIAL
ON
OFF
THERMOSTAT DEMAND
COMBUSTION AIR BLOWER
COMBUSTION AIR PROVE SWITCH
GAS VALVE
IGNITION SPARK
IGNITION TRIAL
THERMOSTAT DEMAND
COMBUSTION AIR BLOWER
NORMAL IGNITION SEQUENCE
TIMINGS NOMINAL
SECONDS 0 5
GAS VALVE
BLOWER
RETRIALS - IGNITION ATTEMPT SEQUENCE - TIMINGS NOMINAL
SECONDS 0 5 30 35
BLOWER
IGNITION CONTROL TIMING
ON
SECONDS 0 30
OFF
GAS VALVE
IGNITION SPARK
BLOWER
IGNITION TRIAL
JOHNSON IGNITION CONTROL
SENSE
30 35 70
END OF
DEMAND
1
FIGURE 15
65 70 100 105
LOCKOUT
FIGURE 16
6 (+3.4, -2.0) SEC.
30
30
1 2 3
42 SEC.
FIGURE 17
Page 24
LED CODES
ON" = NORMAL
OPERATION
0.5 SEC ON / 2.5 SEC OFF
= IN RETRY PERIOD
OFF" = NO POWER OR
DETECTED FAULT
LED
MAIN POWER
FIGURE 14
0 5 110
WATCHGUARD
END OF
THERMOSTAT
DEMAND
HEATING
CYCLE
122 SEC.
GROUND