Haier MRV 5 Series Operating instructions

Trouble Shooting

Content
Part 1. R32 series Trouble Shooting
4-way valve reversing failure.....................................................................................................................................1
Communication error between indoor and oudtoor unit............................................................................................9
Communication error between power module and PCB.........................................................................................18
Compressor start failure..........................................................................................................................................27
DC fan motor failure.................................................................................................................................................34
High pressure switch off failure................................................................................................................................40
Indoor unit overload.................................................................................................................................................52
Temperature sensor failure......................................................................................................................................62
Part 2. MRV 5 series trouble shooting
1.Trouble Shooting
Commnunication between indoor and wired controller failure..................................................................................70
Communication between DC fan motor and indoor PCB failure...............................................................................79
Communication between indoor and display board failure.......................................................................................82
DC fan motor failure.................................................................................................................................................89
DC motor model is wrong.........................................................................................................................................95
Fan module commnication failure............................................................................................................................98
Fan module hardware overcurrent.........................................................................................................................103
Indoor address repeated failure.............................................................................................................................110
Indoor EEPROM failure.........................................................................................................................................115
Indoor oat switch failure.......................................................................................................................................120
Indoor temperature sensor failure..........................................................................................................................128
Indoor unit 50HZ zero-crossing failure...................................................................................................................138
Power module commnication failure......................................................................................................................144
Power module hardware overcurrent.....................................................................................................................149
The compressor out of control...............................................................................................................................157
Troubleshooting for 4-way valve reversing failure..................................................................................................164
Troubleshooting for MRV 5 indoor and outdoor communication failure..................................................................175
Troubleshooting for outdoor temperature sensor failure........................................................................................188
Troubleshooting for the compressor startup failure................................................................................................201
2. Part inspection
MRV 5 outdoor fan motor inspection......................................................................................................................207
MRV 5 power module inspection...........................................................................................................................210

R32 series Trouble Shooting
1. 4-way valve reversing failure.....................................................................................................................................1
2. Communication error between indoor and oudtoor unit...........................................................................................9
3. Communication error between power module and PCB........................................................................................18
4. Compressor start failure..........................................................................................................................................27
5. DC fan motor failure................................................................................................................................................34
6. High pressure switch off failure...............................................................................................................................40
7. Indoor unit overload................................................................................................................................................52
8. Temperature sensor failure.....................................................................................................................................62

4-way valve reversing failure

2
4-way valve reversing failure
Digital tube indication
on outdoor unit (Small
service PCB)
Indication on YR-E16A
Indication on
YR-E17
25
Indication on round panel
Indication in duct unit
Error Code
Return Enter Main
Monday
2011.11.03 10:30AM
Current error Error code:37 20/08/2014 11:20
25
LED4 flash 3 times
LED3 flash 7 times

3
1. Check the wiring connection between
4-way valve and PCB
2. Check the 4-way valve coil
3. Check if the 4-way valve leaks inside
4. Check the coil resistance
5. Check CN5 voltage in PCB
Connection position
Connection status
Troubleshooting Items

4
Check if the wiring connection
between the 4-way stop valve
and PCB is good.
Reconnection

5
Check if the 4-way stop
valve coil is fixed well
Reconnect
the coil

6
Power again，feel the 4-way valve
temperature, check if the
temperature as below photo
Replace the
4-way valve
TIPS:
Check method：
Power again, in cooling mode,
touch the 4 pipes of the 4-way
valve by hand, if the pipe
temperature feels as shown,
the 4-way valve is normal;
otherwise, the 4-way stop valve
is abnormal.
In heating mode, touch the 4
pipes of the 4-way valve by
hand, if the pipe temperature f
eels as shown, the 4-way valve
is normal; otherwise, the 4-way
stop valve is abnormal.
hot cool

7
Check if the coil resistance
of 4-way valve is normal
Replace the coil
2.1±0.2KΩ
20KΩ

8
Power on again, check if the
voltage value about CN5 in
PCB is AC 220~240V
Replace the
outdoor PCB

Communication error between
indoor and outdoor unit

10
Communication error
between indoor and outdoor unit
Digital tube indication
on outdoor unit
Indication on
YR-E17
23
Indication on YR-E16A
Error Code
Return Enter Main
Monday
2011.11.03 10:30AM
Current error Error code:35 20/08/2014 11:20
Indication on round panel
23
Indication in duct unit
LED4 flash 3 times
LED3 flash 5 times

11
Troubleshooting items
1. Check the wiring connection sequence
2. Check connection wire conductive
3. Check the indoor unit error
4. Switch the connection wire
5. Check the outdoor unit wiring connection
6. Check the indoor unit wiring connection

12
Check if the wiring
connection sequence
between indoor and
outdoor unit is correct
change the
wiring
sequence
Outdoor
unit
Indoor
unit
Outdoor
unit
Indoor
unit
A B C D
A B C D
Outdoor
unit
Indoor
unit A B C D
Note:
Outdoor unit terminal A===Indoor unit teriminal A
Outdoor unit terminal B===Indoor unit teriminal B
Outdoor unit terminal C===Indoor unit teriminal C
Outdoor unit terminal D===Indoor unit teriminal D
After that, the same colour wire should conects
the same position, like green colour wire
conects the terminal A positon 1.

13
Check if the connection
wire between indoor and
outdoor unit is conductive
Replace the
connection wire

14
Check if all the indoor
unit is error
the outdoor
unit is error
Panel of Round way
cassette indication
PCB display in duct unit
Running lamp flash
time(LED4) Running light(LED3)
23 3 5
Outdoor unit
Small service PCB
LED1,LED2.......
(light or not)

15
If not all indoor units are error,
switch the connection wire
between the abnormal indoor
unit and normal indoor unit ,
and check whether the fault
is relieved
The outdoor
unit is faulty
Normal indoor unit Abnormal indoor unit
Otherwise，the indoor unit is
abnormal.
Switch the connection wire
Communication error
between indoor and outdoor unit
Digital tube indication
on outdoor unit
Indication on
YR-E17
23
Indication on YR-E16A
Error Code
Return Enter Main
Monday
2011.11.03 10:30AM
Current error Error code:35 20/08/2014 11:20
Indication on round panel
23
Indication in duct unit
LED4 flash 3 times
LED3 flash 5 times

16
According to wiring diagram to
check if the outdoor unit is correct.
Reconnect
23
If connection correct,
please replace the outdoor PCB

17
According to wiring diagram to
check if the indoor unit is correct.
Reconnection
If connection correct,
please replace the indoor PCB