Daikin Altherma HT Service Manual

ESIE09-08B Troubleshooting by Indication on the Remote Controller
Troubleshooting 189
3.48 “LC ” Indoor Unit: Malfunction of Transmission between
Inverter and Control PC Board
Remote Control
Display
LC
Subcode 29
Applicable
Models
All indoor units
Method of
Malfunction
Detection
Check the communication state between inverter PC board and control PC board by micro-
computer.
Malfunction
Decision
Conditions
When the correct communication is not conducted in certain period.
Supposed
Causes
 Malfunction of connection between the inverter microcomputer and indoor control
microcomputer
 Defect of indoor unit PC board [A4P (1
ø) or A5P (3ø)]
 External factor (Noise etc.)
Troubleshooting
Caution
Be sure to turn off power switch before connect or disconnect
connector, or parts damage may be occured.
Are the
connectors of the
inverter PC board and the
control PC board securely
connected?
Replace the inverter PC board
[A4P (1Ø) or A5P (3Ø)] or the control
PC board
Connect a connecting wire, and
then restart operation.
NO
Are there
any broken wires in
the connectors of the
inverter PC board and
the control PC
board?
Repair the broken wires, and then
restart operation.
YES
YES
NO

Daikin Altherma HT Specifications

General

Type	Air-to-water heat pump
Refrigerant	R-410A
Water Outlet Temperature	Up to 80°C
Operating Temperature Range	-20°C to 35°C
Power Supply	3-phase, 400V
Energy Efficiency Class (Heating)	A++