Hitachi RAS-H(V)RNME-AF Service Manual page 405

12 Troubleshooting
77
Alarm code Opentherm communication failure (Only with intelligent thermostat accessory)
• The alarm code is displayed on the LCD User interface.
• The alarm code is displayed on the seven segments of the indoor unit PCB.
• This alarm code is displayed when there is no Opentherm communication for a continuous period of 1 minute.
connections between
PCB1 and RF Receiver
connected correctly?
LCD
CN1-3
CN1-4
Faulty LCD or RF Receiver
(Check it)
Alarm control procedure
The control will continue in normal operation with the following fixed Opentherm values:
- Circuit 1: Uses the last received Room Set-point. The Room temperature is assumed to be equal to the Room
Set-point.
- Circuit 2: Uses the last received Room Set-point. The Room temperature is assumed to be equal to the Room
Set-point.
- Control will not obey the thermostat time programme and OFF function.
N O T E
For more information refer to Room unit installation
395
SMGB0070 rev. 1 - 08/2011
Are the
RF Receiver
TB
No
RF-1
TB2-3
RF-2
TB2-4
Yes
guide.
Wiring check, repair breaking of wire, wrong wiring
Contact your local dealer
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