Grundig GHP-MM08, Service Manual

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Heat Pump Monobloc Inverter / User Manual
202202 Heat Pump Space Heater 50
4.4.9 P08 diagnosis and analysis
4.4.9.1 Diagnosis
When Heat pump shuts down and the contactor of the middle pressure switch MP installed
on the discharge pipe of the compressor keeps open for 3 seconds, the interface will display the
code P08 and heat pump still keeps in the shutdown state until the contactor of the pressure
switch HP2 closes. When the pressure is above 4.2MPa, the contactor of the middle pressure
switch MP will open. When the pressure is below 3.8MPa, the contactor will close.
4.4.9.2 Possible causes
!
The port TS4 of the pressure switch MP (Middle Pressure) on refrigerant system PCB is not
connected properly or has malfunctioned.
!
Refrigerant system PCB is damaged.
4.4.9.3 Analysis and action
The pressure switch MP is loose?
P08
Yes
Ensure the switch is connected
properly
NO
The pressure switch MP has damaged?
Yes
Replace the pressure switch MP
NO
Replace Refrigerant system PCB