12
Failed Thermistor Default Operation
Factory defaults have been provided in the event of failure of
outdoor air thermistor (OAT) and/or outdoor coil thermistor
(OCT).
If the OAT sensor should fail, low ambient cooling will not be
allowed and the one--minute outdoor fan off delay will not occur.
Defrost will be initiated based on coil temperature and time.
If the OCT sensor should fail, low ambient cooling will not be
allowed. Defrost will occur at each time interval during heating
operation, but will terminate after 5 minutes.
If there is a thermistor out of range error, defrost will occur at each
time interval during heating operation, but will terminate after 5
minutes.
Count the number of short and long flashes to determine the
appropriate flash code. Table 6 gives possible causes and actions
related to each error.
OAT Thermistor must be
locked in place with spheri-
cal nib end facing towards
the front of the control box
NO
USE
A12263
Fig. 9 -- Outdoor Air Thermistor (OAT) Attachment
OCT Thermistor
must be secured
tight on stub tube.
A05408
Fig. 10 -- Outdoor Coil Thermistor (OCT) Attachment
Status Codes
Table 6 shows the status codes flashed by the amber status light.
Most system problems can be diagnosed by reading the status code
as flashed by the amber status light on the control board.
The codes are flashed by a series of short and long flashes of the
status light. The short flashes indicate the first digit in the status
code, followed by long flashes indicating the second digit of the
error code.
The short flash is 0.25 seconds ON and the long flash is 1.0 second
ON. Time between flashes is 0.25 seconds. Time between short
flash and first long flash is 1.0 second. Time between code
repeating is 2.5 seconds with LED OFF.
EXAMPLE
:
3 short flashes followed by 2 long flashes indicates a 32 code.
Table 6 shows this to be low pressure switch open.
25H
N
B
6
/25H
N
B
9
