Baxi MK SYSTEM Installation, User And Service Manual page 78

13 Troubleshooting
Code Message
H06.64 HP inverter com
H06.65 HP high temp cooling
H06.66 HP gas temp
H06.67 ODU return high flow
H06.68 ODU air temp sensor
H06.69 3 phase sequence
H06.75 ODU flow error
78
Description
Communication error between the outdoor main control unit and the inverter module of
the heat pump
Error code shown on the digital display of the outdoor unit: H1
If there is a power supply connected to the PCB and to the drive board. Check
whether the PCB LED is on or off. If the LED is off, reconnect the power supply wire.
If the LED is on, check the wire connection between the main PCB and the drive
PCB. If the wire is loose or broken, reconnect the wire or replace it.
Fit a new main PCB or drive board.
HP refrigerant outlet temperature is too high in cooling mode
Error code shown on the digital display of the outdoor unit: Pd
The heat exchanger cover has not been taken off. Remove it.
The heat exchanger is dirty or clogged. Clean the exchanger.
There is insufficient space around the unit for heat exchange.
The fan motor is broken, replace it.
Heat pump gas temperature sensor error
Error code shown on the digital display of the outdoor unit: H3
Check the sensor resistance
The connector for sensor T2B is loose. Reconnect it.
The connector for sensor T2B is wet or contains water.
Drain the water and dry the connector. Add a waterproof adhesive.
Sensor T2B is faulty, replace it with a new sensor.
The heat pump return temperature is higher than the flow temperature in the outdoor
unit
Error code shown on the digital display of the outdoor unit: PP
Check the resistance of the two Tw_out - Tw_in sensors
Check the position of the two sensors.
The water inlet/outlet sensor (TWJn/TW_out) is broken, replace it with a new sensor.
The 4-way valve is jammed. Restart the unit again to allow the valve to change the
direction.
The 4-way valve is broken, replace it with a new valve.
Refrigerant outlet temperature sensor error in air side of heat exchanger of the outdoor
unit
Error code shown on the digital display of the outdoor unit: E5
The connector for sensor T3 is loose. Reconnect it.
The connector for sensor T3 is wet or contains water.
Drain the water and dry the connector. Add a waterproof adhesive.
Sensor T3 is faulty, replace it with a new sensor.
Invalid phase sequence in the 3 phase heat pump power supply
Error code shown on the digital display of the outdoor unit: E1
Check that the power supply cables are correctly connected and avoid phase loss.
Check whether the connections of the neutral and live wires have been reversed.
Water flow error active in the outdoor unit module
Error code shown on the digital display of the outdoor unit: E0 or E8
Check whether the water filter needs cleaning.
Make sure that there is no air in the system (venting).
Check the water pressure. The water pressure must be greater than 1 bar (0.1
MPa).
Check that the pump's speed setting is the highest speed.
Make sure that the expansion vessel is not broken.
Check that the resistance in the hydraulic circuit is not too high for the pump.
If this error occurs during operation in Defrost mode (when heating spaces or do­
mestic water), make sure that the power supply to the backup electric heater is cor­
rectly cabled and the fuses are not blown.
Check that the pump fuse and the PCB fuse are not blown.
The electric circuit is short circuited or open. Reconnect the wire correctly.
The water flow rate is too low.
The water flow rate controller is faulty, it is continuously open or closed. Switch the
water flow rate controller.
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