53
FLAME
LED
The
FLAME
LED is an indication of the
presence of flame.
OFF
– No flame is detected.
Rapid Blink
– Unexpected Flame
Slow Blink
– Marginal Flame Sense
Steady ON
– Normal Flame Detected
STATUS
LED
The
STATUS
LED is an indication of a
fault present.
Steady ON
– Normal Fault detected.
1 Blink
– Ignition failure – 1 HR lockout
2 Blinks
– Pressure switch stuck open
– switch will not close when inducer is
on.
3 Blinks
– Limit switch open – main
limit or roll-out control.
4 Blinks
– Pressure switch stuck
closed. Switch will not open.
5 Blinks
– Not applicable.
6 Blinks
– Line and Neutral reversed.
POWER
LED
The
POWER
LED is an indication of
24ac power to the board.
OFF
– No power (24VAC) to control
board.
ON
– Control is powered.
CFM
LED
The
CFM
LED is an indication of target
airflow. This is a reasonably close
approximation of the airflow pushed by
the blower motor through the furnace.
Because of manufacturing and
measurement tolerances, air density,
humidity, ambient air temperature and
other things, the CFM actually
measured may vary significantly from
this target value.
One Blink represents 100 CFM of target
airflow. A half blink represents approx.
50 CFM. When the blink sequence is
complete, there will be a noticeable
pause of approximately one second
before the sequence repeats. For
example, if elevent and one half blinks
are counted followed by a one second
pause and then eleven and one half
blinks are counted again, the target
airflow is approximtely 1150 CFM.
Because the resolution of this method is
only 50 CFM (half-blinks), the actual
taget CFM could be anywhere between
1125 CFM and 1175 CFM. And, since
this is TARGET airflow, the actual
airflow measured could be much
different than this.’
The
CFM
LED is intended to be for
reference only. The CFM airflow
reported by the furnace control through
blinks of this LED should be only used
as a guide to determine
APPROXIMATE airflow and is not
intended as a laboratory-grade
instrument for determining precise
airflow through the furnace.
WIRING DIAGRAM
Figure 53 is a complete wiring diagram
for the furnace.