59
SERVICING
PCBHR104
Integrated control
module diagnostic/status
LED display shows the
indicated code.
displays ‘---‘ in the
temperature display area.
A
2
Outdoor air
temp sensor
fault
AIR
FLT
A2
Shorted sensor.
Open sensor.
Sensor
disconnected.
Sensor out of
range.
Check sensor
connection.
Replace open/
shorted sensor.
Turn power OFF prior
to repair.
Replace with correct
replacement part.
Heat pump fails to operate
in heating mode.
Integrated control
module diagnostic/status
LED display shows the
indicated code.
displays error message.
A
3
Outdoor coil
temp sensor
fault
COIL
FLT
A3
Shorted sensor
Open sensor.
Sensor.
disconnected.
Sensor out of
range.
Check sensor
connection.
Replace open/
shorted sensor.
Turn power OFF prior
to repair.
Replace with correct
replacement part.
Air conditioner/heat pump
fails to operate.
Integrated control
module diagnostic/status
LED display shows the
indicated code.
E
5
Open fuse
FUSE
E5
Short in low
voltage wiring.
Locate and
correct short
in low voltage
wiring.
Turn power OFF prior
to repair.
Replace fuse with
3-amp automotive type.
Air conditioner/heat pump
fails to operate.
Integrated control
module diagnostic/status
LED display shows the
indicated code.
E
E
Board mis-
operation
FAULT
EE
Compressor
relay contacts
welded.
Replace control.
Turn power OFF prior
to repair
Replace with correct
replacement part.
Air conditioner/heat pump
fails to operate.
Integrated control
module diagnostic/status
LED display shows the
indicated code.
displays error message.
b
0
Circulator
blower motor
is not running
when it
should be
running.
MOTOR
b0
Indoor blower
motor problem.
Communications
error between
indoor and
outdoor unit.
Check indoor
blower motor.
Check indoor
blower motor
wiring.
Check indoor unit
control.
Repair/ replace
any faulty wiring.
Repair/ replace
indoor blower
motor or control.
Turn power OFF prior
to repair.
Applies only to fully
communicating system
thermostat.
Replace with correct
replacement part.
Air conditioner/heat
pump operates at reduced
performance.
Air conditioner/heat pump
operating at low stage
when expected to operate
at high stage.
Integrated control
module diagnostic/status
LED display shows the
indicated code.
b
9
lower than
demanded
LOW ID
AIRFLOW
b9
Indoor blower
motor problem
Restrictive/
undersized
ductwork
Indoor/ outdoor
unit miss-match.
Check indoor
blower motor.
clean/replace as
needed.
Check ductwork;
resize as needed.
Verify indoor and
outdoor units are
properly matched.
Turn power OFF prior
to repair.
Applies only to fully
communicating system
thermostat.
Replace with correct
replacement part. See
and maximum external
static pressure.
sheets for approved
system matches.