Midea Aqua thermal Super Series - Page 88

Aqua thermal Super
87
Part 4 – Diagnosis and Troubleshooting
Possible causes
 Evaporator pressure less than 0.6MPa
 Water flow is too low
 Electronic expansion valve damaged
 Pressure sensor damaged
 Main control board damaged
Procedure
PC
Water flow is too low
Yes
Check whether the water system is clean
and water pump is running
No
Check whether the electronic expansion
valve
1
is damaged
Yes
Replace electronic expansion valve
No
Check whether the pressure sensor
2
is
damaged
Yes
Replace the pressure sensor
No
Replace main control board
Note:
1． Electronic expansion valve coil connections are port CN70, CN71 and CN72 on the main PCB (labeled31, 32, 30 in Part 4, 2.2.1 Main PCB
component). The normal resistances between EXV coil wiring terminals is 40-50Ω. If any of the resistances differ from the value, the EXV
coil has malfunctioned.
2． Pressure sensor connection is port CN41 on the main PCB (labeled 19 in Part 4, 2.2.1 Main PCB component). 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.
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