Lennox G24M SERIES Installation Instructions

HEATINGSEQUENCECONTINUED
NORMALHEATINGMODE ABNORMALHEATINGMODE
15-SECOND COMBUSTION AIR BLOWER PREPURGF I
11
N T ATED BY CLOSED PRESSURE SW TCH. /
YES
[ IGNITOR WARM-UP -- 20 SECONDS. I
YES _
4-SECOND TRIAL FOR IGNITION.
GAS VALVE OPENS. IGNITOR ENERGIZED FOR
I SECOND AFTER VALVE OPENS.
NO FLAME SENSED DURING THIS PERIOD.
YES
I FLAME STABILIZATION PERIOD. I
4 SECONDS _
FLAME RECTIFICATION CURRENT CHECK /
CAN FLAME BE PROVEN WITHIN 4
P
SECONDS AFTER GAS VALVE OPENS?
( > 0.15 microamps)
FLAME PRESENT? I--_
YES _ NO_[
FLAME SIGNAL ABOVE 0.7 MICROAMPS?
YES _
I
I
INDOOR BLOWER ON DELAY BEGINS /
/45 seconds.)
YES _
[ INDOOR BLOWER ON ACB HEAT SPEED. 1ACC. TERMINAL ENERGIZED
PRIMARY AND SECONDARY LIMIT I
SWITCHES CLOSED?
I
YES 1
._GAS VALVE OFF. COMBUSTION AIR BLOWER ON. _O
INDOOR BLOWER OFF.
HAS CONTROL FAILED TO SENSE FLAME FOR
FIVE CONSECUTIVE TRIES DURING A SINGLE
HEAT DEMAND?
/
IGNITION WATCHGUARD MODE. GAS VALVE OFF. I .
COMBUSTION AIR BLOWER OFF, I y_S_YES
INDOOR BLOWER OFF WITH DELAY
LED #1 - ALT, SLOW FLASH, LED #2 - ALT. SLOW FLASH,
S 60-M NUTE RESET PER OD COMPLETE? /
/
YES T
HAS CONTROL RESET IGNITION I
SEQUENCE FOUR TIMES?
LOW FLAME SIGNAL |
(Does not affect operationof control)
J
LED #1 - SLOW FLASH
LED #2 - FAST FLASH
GAS VALVE DE-ENERGIZED.
COMBUSTION AIR BLOWER DE-ENERGIZED.
INDOOR BLOWER ON UNTIL SWITCH CLOSES.
LED #1 - SLOW FLASH. LED #2 - ON.
IS LIMIT SWITCH CLOSED?
LIMIT SWITCH WATCHGUARD MODE.
GAS VALVE OFE COMBUSTION AIR
BLOWER OFF.
INDOOR SLOWER OFF WITH DELAY
LED #1- SLOW FLASH, LED #2 - ON.
YES
NO L IS 60-MINUTE RESET PERIOD
I ROLLOUTyEsSWITCH_CLOSED? _ [ COMPLETE?
/ HAS PRIMARY/SECONDARY I ,
LIMIT AUTOMATIC RESET TIME I
I-.--I COMBUSTION AIR PRESSURE EXCEEDED 3 MINUTES? I
l SWITCH CLOSED?
/ GAS VALVE OFF. COMBUSTION AIR BLOWER OFF.
YES
f INDOOR BLOWER OFF WITH DELAY.
I LED #1 - ON. LED #2 - SLOW FLASH.
I THERMOSTAT DEMAND SATISFIED. I LSEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES
YES
I {,_) #1 & #2 SIMULTANEOUS SLOW FLASHES. I
YES
COMB. AIR BLOWER CONTINUES 5-SECOND
POST PURGE AFTER T'STAT DEMAND IS SATISFIED.
INDOOR AIR BLOWER COMPLETES SELECTED
OFF" DELAY BEFORE SHUTT NG OFF.
;70
-S
NO
GAS VALVE DE-ENERGIZED.COMBUSTION AIR BLOWER ON. ]
INDOOR BLOWER OFF WITH DELAY IYES=
LED #1 - OFF. LED #2 - SLOW FLASH.
HAS CAB SWITCH CLOSED IN 2.5 MINUTES? |
NO
I 5-MINUTE PRESSURE SWITCH I
WATCHGUARD MODE.
Page 30

Lennox G24M SERIES Specifications

General

Brand	Lennox
Model	G24M SERIES
Category	Furnace
Language	English