Midea MHC - V18W/D2RN8 - Page 81

M thermal Mono
80 202008
Midea M thermal Mono
Service Manual
Procedure 4.22.4
PP
Water side heat exchanger water inlet /
outlet temperature sensor is loose
1
Yes
Ensure the temperature sensor is
connected properly
No
Water side heat exchanger water inlet /
outlet temperature sensor has
short-circuited or failed
2
Yes
Replace the temperature sensor
No
The 4-way valve is blocked or damaged
3
Yes
Replace the 4-way valve
No
Replace outdoor main PCB
Notes:
1. Water side heat exchanger water inlet temperature sensor and water side heat exchanger water outlet temperature sensor connections are port CN6 on
the hydronic system main PCB (labeled 10 in Figure 4-2.1).
2. Set a multi-meter to buzzer mode and test any two terminals of sensor. If the resistance is too low, the buzzer sounds, which means the sensor has
short-circuited. If the resistance is not consistent with the sensor s resistance characteristics table, the sensor has failed. Refer to Table 4-5.3
3. Restart the unit in cooling mode to change the refrigerant flow direction. If the unit does not operate normally, the 4-way valve is blocked or damaged.
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