Midea MHC-V12W/D2RN8-B - Page 108

M thermal Mono
106 200204
Midea M thermal Mono Service Manual
Procedure
PP/Hb
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 8 in Figure 4-2.1 in Part 4, 2.2 “Min PCB for Hydronic System”).
2. Measure sensor resistance. If the resistance is too low, the sensor has short-circuited. If the resistance is not consistent with the sensor’s resistance
characteristics table, the sensor has failed. Refer to Part 2, 1 “Layout of Functional Components” and to Table 4-5.1 to 4-5.2 in Part 4, 5.1 “Temperature
Sensor Resistance Characteristics”.
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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