Hoshizaki KM-500MAH Instruction Manual page 23

[2] Remove the water from the potable water supply line:
1) Remove the Front Panel. (Except water-cooled model)
2) Move the Control Switch, on the Control Box, to the "OFF" position.
3) Wait 3 minutes.
4) Close the Potable Water Supply Line Shut-off Valve and open the Potable Water Supply
Line Drain Valve. See Fig. 9.
5) Allow the line to drain by gravity.
6) Attach compressed air or carbon dioxide supply to the Potable Water Line Drain Valve.
7) Move the Control Switch to the "ICE" position.
8) Blow the potable water line out using compressed air or carbon dioxide.
[3] Drain the Potable Water Tank:
1) Turn off the power supply.
2) Move the Control Switch, on the Control Box, to the "OFF" position.
3) Remove the Base Cover.
4) Remove one end of the Pump Tubing, and drain the Water Tank.
5) Replace the Pump Tubing and the Base Cover in their correct positions.
6) Remove all ice from the Storage Bin, and clean the Storage Bin.
7) Replace the Front Panel in its correct position.
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