Troubleshooting Guide

Table Of Contents
MRCOOL Universal Service Manual
12
2.3.5 Forced Defrost Control
Press and hold "SW1" for about 5s to enter the first level menu of the debugging mode, the outdoor unit
mainboard LED displayer flashes. Under the first level menu, short press "SW1" to switch various functions. After
switching to "06", short press "SW2" or "SW3" to enter the forced defrosting mode, "ON" means open, "OF"
means close, and then short press "SW1" to save. During debugging, if no operation is performed within 10s, the
debugging mode interface will be exited.
2.3.6 Refrigerant Recovery Control
Press and hold "SW1" for about 5s to enter the first level menu of the debugging mode, the outdoor unit
mainboard LED displayer flashes. Under the first level menu, short press "SW1" to switch various functions. After
switching to "08", short press "SW2" or "SW3" to enter the refrigerant recovery control mode, "ON" means open,
"OF" means close. And then short press "SW1" to save. During debugging, if no operation is performed within
10s, the debugging mode interface will be exited.
2.3.7 Forced Operation Control
Press and hold "SW1" for about 5s to enter the first level menu of the debugging mode, the outdoor unit
mainboard LED displayer flashes. Under the first level menu, short press "SW1" to switch various functions. After
switching to "09", short press "SW2" or "SW3" to enter the forced operation control mode, "01" denotes that turn
on the forced operation cooling mode; "02" denotes that turn on the forced operation cooling mode; "OF"
Level 1
(Default)
Level 2
Level 3