Midea
V6R
Series Service Manual
ODU stop valves are closed
High pressure sensor connection on
outdoor main PCB is loose
1
Ensure the sensor is connected properly
High pressure sensor has short-circuited
or failed
2
Insufficient refrigerant caused by
refrigerant leakage
3
Add refrigerant and inspect system for
leaks
The low pressure side is blocked, caused
by crushed or bent pipe, closed EEV or
dirty filter
4
Inspect the system and fix the error. If the
filter is blocked by ice, the piping should
be cleaned
The evaporator heat exchange is poor
5
Inspect the system and fix the error
Replace the outdoor main PCB
Notes:
1. High pressure sensor connection is port CN17 on the outdoor main PCB.
2. Measure the resistance among the three terminals of the pressure sensor. If the resistance is of the order of mega Ohms or infinite, the pressure sensor has
failed.
3. An insufficiency of refrigerant causes compressor discharge temperature to be higher than normal, discharge and suction pressures to be lower than normal
and compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. These issues disappear once sufficient refrigerant has
been charged into the system.
4. A low pressure side blockage causes compressor discharge temperature to be higher than normal, suction pressure to be lower than normal and compressor
current to be lower than normal, and may cause frosting to occur on the suction pipe.
5. In cooling mode check indoor heat exchangers, fans and air outlets for dirt/blockages. In heating mode check outdoor heat exchangers, fans and air outlets
for dirt/blockages.