INSTALLATION INSTRUCTIONS - Lennox
INSTALLATION INSTRUCTIONS - Lennox
INSTALLATION INSTRUCTIONS - Lennox
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Troubleshooting: Heating Sequence of Operation (Continued)<br />
HEATING SEQUENCE CONTINUED<br />
NORMAL HEATING MODE<br />
ABNORMAL HEATING MODE<br />
15-SECOND COMBUSTION AIR INDUCER PREPURGE<br />
INITIATED BY CLOSED PRESSURE SWITCH.<br />
YES<br />
IGNITOR WARM-UP −− 20 SECONDS.<br />
YES<br />
4-SECOND TRIAL FOR IGNITION.<br />
GAS VALVE OPENS. IGNITOR ENERGIZED FOR<br />
UP TO 4 SECONDS.<br />
YES<br />
FLAME STABILIZATION PERIOD.<br />
4 SECONDS<br />
FLAME RECTIFICATION CURRENT<br />
CHECK. CAN FLAME BE PROVEN WITHIN<br />
4 SECONDS AFTER GAS VALVE OPENS?<br />
(0.5 microamps)<br />
YES<br />
FLAME PRESENT?<br />
YES<br />
FLAME SIGNAL 1.5 MICROAMPS OR GREATER?<br />
YES<br />
INDOOR BLOWER ON<br />
AFTER 45−SECOND DELAY<br />
YES<br />
PRIMARY AND SECONDARY LIMIT<br />
SWITCHES CLOSED?<br />
YES<br />
NO<br />
NO<br />
NO<br />
NO<br />
NO<br />
IS VOLTAGE ABOVE 90 VOLTS?<br />
YES<br />
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.<br />
INDOOR BLOWER OFF.<br />
HAS CONTROL FAILED TO SENSE FLAME FOR<br />
FIVE CONSECUTIVE TRIES DURING A SINGLE<br />
HEAT DEMAND?<br />
WATCHGUARD MODE. GAS VALVE OFF.<br />
COMBUSTION AIR INDUCER OFF.<br />
INDOOR BLOWER OFF WITH DELAY<br />
LEDs SIGNAL WATCHGUARD FAILURE CODE.<br />
IS 60-MINUTE RESET PERIOD COMPLETE?<br />
HAS CONTROL RESET IGNITION<br />
SEQUENCE FOUR TIMES?<br />
LOW FLAME SIGNAL<br />
(Does not affect operation of control)<br />
LED #1 −− SLOW FLASH<br />
LED #2 −− FAST FLASH<br />
GAS VALVE DE−ENERGIZED.<br />
COMBUSTION AIR INDUCER DE−ENERGIZED.<br />
INDOOR BLOWER ON UNTIL SWITCH CLOSES.<br />
LED #1 −− SLOW FLASH. LED #2 −− ON.<br />
IS LIMIT SWITCH CLOSED?<br />
YES<br />
HAS PRIMARY / SECONDARY<br />
LIMIT RESET TIME<br />
EXCEEDED 3 MINUTES?<br />
NO<br />
LEDS SIGNAL<br />
ALTERNATING<br />
FAST FLASH UNTIL<br />
VOLTAGE IS ABOVE<br />
95 VOLTS, THEN<br />
RESTARTS HEATING<br />
SEQUENCE.<br />
YES<br />
NO<br />
YES<br />
NO<br />
LIMIT SWITCH WATCHGUARD<br />
MODE. GAS VALVE, COMB. AIR<br />
INDUCER AND INDOOR BLOW-<br />
ER OFF. LEDs SIGNAL LIMIT<br />
SWITCH OPEN UNTIL MAIN<br />
POWER IS<br />
YES<br />
NO<br />
YES<br />
INTERRUPTED OR<br />
T’STAT IS CYCLED<br />
OFF/ON FOR 1 SEC.<br />
MINIMUM. 60−MINUTE<br />
WATCHGUARD PE-<br />
RIOD STARTS AT<br />
TIME LIMIT CLOSES.<br />
IS 60−MIN. PERIOD<br />
COMPLETE?<br />
ROLLOUT SWITCH CLOSED?<br />
YES<br />
COMBUSTION AIR PRESSURE<br />
SWITCH CLOSED?<br />
YES<br />
THERMOSTAT DEMAND SATISFIED.<br />
YES<br />
LED #1 & #2 SIMULTANEOUS SLOW FLASHES.<br />
YES<br />
COMB. AIR INDUCER CONTINUES 5-SECOND<br />
POST PURGE AFTER T’STAT DEMAND IS SATISFIED.<br />
INDOOR AIR BLOWER COMPLETES SELECTED OFF"<br />
DELAY BEFORE SHUTTING OFF.<br />
NO<br />
NO<br />
GAS VALVE POWER OFF.<br />
COMBUSTION AIR INDUCER POWER ON.<br />
INDOOR BLOWER ON<br />
LED #1 −− ON. LED #2 −− SLOW FLASH.<br />
SEQUENCE HOLDS UNTIL ROLLOUT SWITCH IS RESET<br />
AND MAIN POWER IS INTERRUPTED OR<br />
THERMOSTAT IS CYCLED OFF/ON FOR 1 SEC. MINIMUM.<br />
GAS VALVE DE−ENERGIZED.<br />
COMBUSTION AIR INDUCER ON.<br />
INDOOR BLOWER OFF WITH DELAY<br />
LED #1 −− OFF. LED #2 −− SLOW FLASH.<br />
HAS CAB SWITCH CLOSED IN 2.5 MINUTES?<br />
NO<br />
5-MINUTE PRESSURE SWITCH<br />
WATCHGUARD MODE.<br />
YES<br />
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