Servicing Mode; Remove The Cabinet Front Plate; Test Run; Proper Pump Down Procedure - Panasonic WH-MHF12G9E8 Service Manual

14. Servicing Mode

14.1 Remove The Cabinet Front Plate

1. Remove the 5 mounting screws as shown in the illustration.
2. Slide the cabinet front plate downward to release the pawls.
Then, pull it toward front to remove it.

14.2 Test Run

1. Fill up the Tank Unit with water. For details refer to Tank Unit installation instruction and operation instruction.
2. Antifreeze agent must be added into water circuit to prevent freezing of water when outdoor ambient
temperatures is low. Recommended antifreeze: Propylene glycol: 40% (equivalent to -20°C)
3. Set ON to the Mono bloc unit and RCCB. Then, for remote control operation please refers to (Mono bloc) Air-
to-Water Heatpump's operation instruction.
4. For normal operation, pressure gauge reading should be in between 0.05 MPa and 0.3 MPa. If necessary,
adjust the water pump speed accordingly to obtain normal water pressure operating range. If adjust water
pump speed cannot solve the problem, contact your local authorized dealer.
5. After test run, please clean the external filter. Reinstall it after finish cleaning.

14.3 Proper Pump Down Procedure


Strictly follow the steps below for proper pump down procedure. Explosion may occur if the steps are not
followed as per sequence.
1. Press the "SERVICE" switch on remote control to enter SERVICE mode. Operate the system in Sr : 01 mode
for pump down operation.
2. After 10~15 minutes, (after 1 or 2 minutes in case very low ambient temperatures (< 10°C)), fully close 2 way
valve.
3. After 3 minutes, fully close 3 way valve.
4. Press the "OFF/ON" switch on remote control to stop pump down operation.
5. Remove the refrigerant piping.
Mounting screws
79
Cabinet Front Plate
Mounting
screws