Hitachi RAW-35RHC - Troubleshooting by Alarm Code (Related to Tank)

6 Troubleshooting
Indoor unit
SMGB0135 rev.0 - 06/2020
72
6.2.2 Troubleshooting by alarm code (related to tank)
Alarm code
03
Abnormal transmission between the indoor unit and the outdoor unit
• This alarm is displayed when an Outdoor unit is not detected for three minutes after the normal transmission between
the indoor units and the outdoor units. Also an abnormal transmission is maintained for 30 seconds after the micro-
computer is Power ON. The alarm is displayed when the abnormal transmission is maintained for 30 seconds from
the starting of the outdoor unit.
Alarm code
16
DHW tank thermistor abnormally (THM
DHWT
)
• This alarm code is displayed when the thermistor is short-circuited (greater than 100ºC) or cut (less than -10ºC) when
DHW is enabled.
• This alarm forces all operations to stop (Outdoor & Indoor Units).
• The unit should be stopped to release the alarm.
No
Connect it
Yes
Yes
No
Is THM
DHWT
connected to
CN4 (pin 3 and pin 4)?
Faulty thermistor
(Change it)
Is resistance of
THM
DHWT
between 0.25
kΩ and 21 kΩ?
Is the
temperature of
THM
DHWT
between 100ºC
and -10ºC?
Faulty PCB (Check
PCB)
No
Check correct position
of THM
DHWT
and correct
it
Yes
72,05
37,92
20,96
12,10
7,26
4,51
2,89
1,91
1,29
0,89
0,63
0,46
0,34
0,25
0,19
0,15
0,13
0
10
20
30
40
50
60
70
80
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130
Thermistor resistance (kΩ)
Temperature (ºC)
Temperature (ºC)
Thermistor resistance (kΩ)
Thermistor resistance characteristics