Sinclair SCV-EB Series Service Manual page 62

5.18 Hb/PP Troubleshooting
5.18.1 Digital display output
5.18.2 Description
 PP indicates | Tw_out-Tw_in | abnormal protection.
 Hb indicate three times PP protection and Tw_out below 7 ℃
 Heat pump stops running.
 Error code is displayed on the refrigerant system PCB digital tube and user interface.
5.18.3 Procedure
Water side heat exchanger water inlet /
outlet temperature sensor is loose
Water side heat exchanger water inlet /
outlet temperature sensor has
short-circuited or failed
The coil or plug of 4-way valve are not
connected properly
4-way valve is blocked or damaged
Replace refrigerant system PCB
Notes:
1. Inlet water temperature sensor(TW_in), outlet water temperature sensor(TW_out) connection are port CN6 on the hydro system PCB.
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.
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.
60
Hb/PP
1
No
2
No
No
3
No
Ensure the temperature sensor is
Yes
connected properly
Yes
Replace the temperature sensor
Ensure coil or plug of 4-way valve are
Yes
connected properly
Yes
Replace the 4-way valve