Lennox G23(X) User Manual

3DJH 
PROBLEM 1: UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODE
Condition Possible Cause Corrective Action / Comments
1.5
- On initial power-up the combus-
tion air blower remains energized.
Di ti li ht fl h th i
1.5.1
Improper ground to the unit.
ACTION 1 - Check that the unit is properly
ground.
ACTION 2 - Install a proper main ground to
the unit
g
- Diagnostic lights flash the im-
proper main ground.
1.5.2
6-Pin connector is improperly at-
tached to the circuit board.
ACTION 1 - Check 6-pin connector for proper
installation. Correctly insert connector into
control.
LED#1-Alternating Fast Flash
LED#2-Alternating Fast Flash
1.5.3
Line voltage is below 75V.
ACTION 1 - Check that the line voltage is
above 75V. Determine cause of voltage drop
and supply correct voltage to the control.
PROBLEM 2: UNIT FAILS TO OPERATE IN THE COOLING OR HEATING MODE, BUT COMBUSTION
AIR BLOWER OPERATES CONTINUOUS. UNITS WITH CONTROL BOARDS DATE CODED AFTER
NOV. 1 1997, WILL OPERATE IN COOLING BUT NOT IN THE HEATING MODE, WITH COMBUS-
TION AIR BLOWER CYCLING 5 SECONDS ON 55 SECONDS OFF.
Condition Possible Cause Corrective Action / Comments
2.1
- On initial power-up the combus-
tion air blower remains energized.
- Diagnostic lights flash the im-
proper main ground.
- Units with control boards date
2.1.1
Open ignitor circuit.
ACTION 1 - Check for correct wiring andloose
connections in the ignitor circuit. Check mult-
plug connections for correct installation.
Units with control boards date
coded after Nov.1 1997; combus-
tion air blower will cycle 5 seconds
on 55 seconds off.
LED#1-Alternating Fast Flash
LED#2-Alternating Fast Flash
2.1.2
Broken or failed ignitor.
ACTION 1 - Unplug ignitor and read resis-
tance across ignitor. If resistance does not
read between 10.9and 19.7ohms, replacethe
ignitor.
PROBLEM 3: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR BLOWER DOES
NOT ENERGIZE
Condition Possible Cause Corrective Action / Comments
3.1
- Unit operates with a cooling or
continuous fan demand.
- Combustion air blower will not
start with a Heating demand.
- Diagnostic lights flash the limit
failure mode
3.1.1
Primary or secondary (if equipped
) limit open.
ACTION 1 - Check continuity across
switch(es). Switches reset automatically
upon cool down.
ACTION 2 - Check for restrictions on blower
inlet air (including filter) and outlet air. Deter-
mine cause for limit activation before placing
unit back in operation.
f
a
il
ure mo
d
e.
LED#1-Slow Flash,
LED#2-On
3.1.2
Miswiring of furnace or improper
connections at limit switch(es).
ACTION 1 - Check for correct wiring andloose
connections. Correct wiring and/or replace
any loose connections.
3.2
- Unit operates with a cooling and
continuous fan demand.
- Combustion air blower will not
start with a Heating demand.
- Diagnostic lights flash the pres-
sure switch failure code
3.2.1
Miswiring of furnace or improper
connections to combustion air
blower.
ACTION 1 - Check for correct wiring andloose
connections. Correct wiring and/or replace
any loose connections.
sure switch failure code.
LED#1-Off,
LED#2-Slow Flash
3.2.2
Pressure switch stuck closed.
ACTION 1 - Check that the pressure switch is
open without the combustion air blower op-
erating. Replace if defective.

Lennox G23(X) Specifications

General

Brand	Lennox
Model	G23(X)
Category	Furnace
Language	English