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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 minute
Watchguard mode depending on in
termittent 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 signal.
ACTION 1 −
Check that the sensor is properly lo
cated.
ACTION 2 −
Check that the sense wire is properly
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 diag
nostic 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.
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: RF STATIC DURING TIME FOR IGNITION
Condition
Possible Cause
Corrective Action/Comments
8.0
− AM radio interference
8.1.1
Ignitor operation
ACTION 1
−
Call Technical Support, Dallas