Lennox G26 Series User Manual

Page 48
PROBLEM 6: BURNERS LIGHT WITH HEATING DEMAND BUT UNIT SHUTS DOWN
PREMATURELY (CONT.)
6.5
− Combustion air blower energizes
with a heating demand.
− Burners light.
− Diagnostic lights flash watch guard
flame failure.
− NOTE" Unit might go into 60 min-
ute Watchguard mode depending on
intermittent nature of sensor signal.
LED#1−Alternating Slow Flash
LED#2−Alternating Slow Flash
6.5.1
Loose sensor wire connection
causes intermittent loss of flame sig-
nal.
ACTION 1 − Check that the sensor is properly lo-
cated.
ACTION 2 − Check that the sense wire is proper-
ly attached to both the sensor and the control.
Pay extra attention to the pin connectors.
PROBLEM 7: CONTROL SIGNALS LOW FLAME SENSE DURING HEATING MODE
Condition Possible Cause Corrective Action/Comments
7.0
− Unit operates correctly but the
diagnostic lights flash low flame
sense code
7.1.1
Sense rod is improperly located on
the burner.
ACTION 1 − Check the sense rod for proper loca-
tion on the burner. Properly locate the sense rod
or replace if rod cannot be located correctly.
sense
code
.
LED#1−Slow Flash
LED#2−Fast Flash
7.1.2
Sense rod is contaminated.
ACTION 1 − Check sense rod for contamination
or coated surface. Clean the sense rod with steel
wool or replace sensor. DO NOT USE SAND PA-
PER TO CLEAN ROD. SAND PAPER WILL
CONTRIBUTE TO THE CONTAMINATION
PROBLEM.
PROBLEM 8: INDOOR BLOWER FAILS TO OPERATE IN COOLING, HEATING, OR CONTINUOUS
FAN MODE
Condition Possible Cause Corrective Action/Comments
8.0
− Indoor blower fails to operate in
continuous fan, cooling, or heating
mode.
8.1.1
Miswiring of furnace or improper con-
nections at control or indoor blower
motor.
ACTION 1− Correct wiring and/or replace any
loose connections. Check for correct wiring and
loose connections.
8.1.2
120V is not being supplied to the in-
door air blower or blower motor fail-
ure.
ACTION 1 − Check for 120V at the various calls
for indoor blower by energizing "Y", "G", and "W"
individually on the low voltage terminal strip.
Note that when "W’ is energized, the blower is
delayed 45 seconds. If there is 120V to each mo-
tor tap but the blower does not operate, replace
the motor.
8.1.3
Defective control board
ACTION 1 − If there is not 120V when "Y", "G", or
"W" is energized, replace the control.
PROBLEM 9: RF STATIC DURING TIME FOR IGNITION
Condition Possible Cause Corrective Action/Comments
−AM radio interference Ignitor operation
ACTION 1− Call Technical Support, Dallas

Lennox G26 Series Specifications

General

Heating Stages	Single-stage
Blower Motor	PSC (Permanent Split Capacitor)
Gas Valve	Single-stage
Vent Type	Natural Draft
Fuel Type	Natural Gas or Propane
Blower Motor Type	PSC
Warranty	5-Year Limited Warranty on covered components
Heating Capacity	44, 000 to 132, 000 BTU/h
Filter Type	Standard