Johnson Controls HMH72B36 User Manual

Table 10: Outdoor unit fault codes
Fault code Fault description Possible reasons for fault Resolution Comments
5
Cooling freezing
protection (the
indoor coil
temperature is too
low) or heating
overload (the indoor
coil temperature is
too high)
1. Indoor unit airflow
restriction.
2. The room
temperature is too low
in cooling mode or the
room temperature is
too high in heating
mode.
3. The filter is dirty.
4. The duct resistance is
too high resulting in
low airflow.
5. The selected indoor
fan speed is too low.
6. The indoor unit
is not installed in
accordance with
the installation
instructions, and the
air inlet is too close to
the air outlet.
1. Check if the indoor
fan, indoor fan
motor, and indoor
coil function
normally.
2. Normal protection.
3. Clean the filter.
4. Correct the duct
system.
5. Correct the indoor
fan speed.
6. Reinstall the indoor
unit referring to
the installation
instructions to
resolve issues.
7
Communication fault
between the indoor
unit and outdoor unit
1. The low-voltage
cable is connected
incorrectly between
the indoor unit and
the outdoor unit.
2. The low-voltage
connection is loose.
3. The low-voltage cable
is damaged.
4. The outdoor control
board has failed.
5. The low-voltage circuit
fuse is open.
6. The low-voltage cable
is incorrect.
1. Reconnect the
connection cable
referring to the
wiring diagram.
2. Reconnect the low-
voltage cable.
3. Replace the low-
voltage cable.
4. Replace the outdoor
control board.
5. Check the low-
voltage circuit, and
adjust the DIP switch
and the short-circuit
fuse.
6. Choose suitable low-
voltage cable. Refer
to the installation
instructions.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump36
Johnson Controls Ducted Systems

Johnson Controls HMH72B36 Specifications

General

Brand	Johnson Controls
Model	HMH72B36
Category	Heat Pump
Language	English