16
Status Codes
Table 3 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 second ON and the long flash
is 1.0 second ON. Time between flashes is 0.25 second. Time
between short flash and first long flash is 1.0 second. Time
between code repeating is 2.5 seconds with LED OFF.
Count the number of short and long flashes to determine the
appropriate flash code. Table 3 gives possible causes and actions
related to each error.
Example:
3 short flashes followed by 2 long flashes indicates a
32 code. Table 3 shows this to be low pressure switch open.
Table 3—Status Codes
OPERATION
FAULT
AMBER LED
FLASH CODE
POSSIBLE CAUSE AND ACTION
Standby – no call for
unit operation
None
On solid, no
flash
Normal operation
Cool/Heat Operation
None
1, pause
Normal operation
System Communica-
tions Failure
16
Communication with user interface lost. Check wiring to UI, indoor
and outdoor units
High Pressure Switch
Open
31
High pressure switch trip. Check refrigerant charge, outdoor fan
operation and coils for airflow restrictions.
Low Pressure Switch
Open
32
Low pressure switch trip. Check refrigerant charge and indoor air
flow
Control Fault
45
Outdoor unit control board has failed. Control board needs to be
replaced.
Brown Out
(24 v)
46
The control voltage is less than 15.5v for at least 4 seconds. Com-
pressor and fan operation not allowed until control voltage is a mini-
mum of 17.5v. Verify control voltage.
Outdoor Air Temp
Sensor Fault
53
Outdoor air sensor not reading or out of range. Ohm out sensor
and check wiring
Outdoor Coil Sensor
Fault
55
Coil sensor not reading or out of range. Ohm out sensor and check
wiring
Thermistors out of
range
56
Improper relationship between coil sensor and outdoor air sensor.
Ohm out sensors and check wiring.
Thermal Cutout
72
Compressor voltage sensed after start---up, then absent for 10 con-
secutive seconds while cooling demand exists. Possible causes are
internal compressor overload trip or loss of high voltage to com-
pressor without loss of control voltage.
Contactor Shorted
73
Compressor voltage sensed when no demand for compressor op-
eration exists. Contactor may be stuck closed or there is a wiring
error.
No 230V at Compres-
sor
74
Compressor voltage not sensed when compressor should be start-
ing. Disconnect may be open or contactor may be stuck open or
there is a wiring error.
Thermal Lockout
82
Thermal cutout occurs in three consecutive cycles. Unit operation
locked out for 4 hours or until 24v power recycled.
Low Pressure Lock-
out
83
Low pressure switch trip has occurred during 5 consecutive cycles.
Unit operation locked out for 4 hours or until 24v power recycled.
High Pressure Lock-
out
84
High pressure switch trip has occurred during 5 consecutive cycles.
Unit operation locked out for 4 hours or until 24v power recycled.
25H
PA
