375
Troubleshooting
Alarm code
76
Freeze Protection Stop by indoor unit temperature thermistors
● Alarm code is displayed on the master controller/ the 7-segment of O.U. display PCB / the 7-segment of I.U. PCB1.
● This alarm code is displayed when the following conditions are detected and the same condition occurs three times or
more within 3 hours
- Condition 1: TL+ TowHP≤4[°C] and TL≤1[°C] lasting for 180s, during defrosting.
- Condition 2: Meet any of following conditions during cooling operation:
(1) TL+ TowHP ≤ 4[°C] and TL ≤ 1[°C] lasting for 180s.
(2) [TL ≤ -4°C and Tg ≤ 8°C] or [Tg ≤ 1°C] lasting for 240s.
(3) [TL≤ -16°C and Tg≤ 8°C] or [Tg ≤ -1°C] lasting for 60s.
● Reset the unit to release the alarm.
Thermistor Connector
Tg THM4
TL THM5
TowHP THM3
No
Is the water
refrigerant temperature
(Tg, TL and TowHP)
correctly measured?
Faulty I.U. PCB1
(Check I.U. PCB1)
Are the connectors
correctly connected?
Are thermistors
Tg, TL and TowHP correct?
(Refer to Alarms 13/14/17
procedures)
Yes
Yes
Yes
1
Wiring check, repair breaking of wire, wrong wiring
Check Tg, TL and TowHP and replace it
No
No
Contact your local dealer
2
3
4
5
6
7
8
9
10
Refer to Alarm 70 procedures
Check that the refrigerant thermistors
(Tg, TL and TowHP) are positioned correctly
Check to make sure the unit is operating within
operating range
Check for shortage of refrigerant
Clogging of plate heat exchanger
Clogging of filter in shut-off valve with filter
Check to make sure the minimum required flow
rate is reached
Make sure that the water volume of the installation
is above minimum required for the unit
Expansion valve malfunction
Contact your local dealer
To Next Page
