Hydro Unit
Diagnostic functional operation
Check
code
Operational cause
The 4-way valve inversion error
P19
High pressure protection operation
P20
Outdoor fan system error
P22
Short circuit of the compressor
driver element error
P26
Compressor rotor position error
P29
Backup
Automatic
present
reset
1. Check the operation of the 4-way valve unit or the coil
characteristics.
2. Defect of the pulse motor valve.
×
O
3. Check the resistance value of the heat exchange
temperature sensor (TE) and the suction temperature
sensor (TS).
1. Check that the service valve is fully open.
2. Defect of the pulse motor valve.
3. Check the outdoor fan system (including clogging).
×
O
4. Over-filling of refrigerant.
5. Check the resistance value of the heat exchange
temperature sensor (TL) and the water outlet
temperature sensor (TWO).
1. Check the lock status of the motor fan.
2. Check the connection of the fan motor cable
×
O
connector.
3. Check the power supply voltage.
1. Abnormality occurs when operating with the
compressor wiring disconnected ... Check the
control board.
×
O
2. No abnormality occurs when operating with the
compressor wiring disconnected ... Compressor rare
short.
1. Even if the connection lead wire of the compressor is
disconnected, it stops due to an abnormality in the
position detection ... Replace the inverter control
×
board.
O
2. Check the wire wound resistor of the compressor.
Short circuit
... Replace the compressor.
– 45 –
Installation Manual
Determination and action
EN
44-EN