Gree GUHD09NK3FO Service Manual page 86

E2 Freeze Protection
Freeze protection is normal protection but not abnormal malfunction. If freeze protection occurs frequently
and air outlet.
E3 stands for three statuses:
(1). Low pressure protection (48K\60K);
(2). Refrigerant lacking protection;
(3). Refrigerant recycling mode;
If enter refrigerant recycling mode through special operation, the displayed E3 is not an error code. It
will be eliminated when exiting refrigerant recycling mode.
If you do not want to have refrigerant lacking protection, you can enter the debugging mode through
wired controller and then cancel the refrigerant lacking protection mode.
E3 protection
Check if the
system low
pressure is lower
than 0.05MPa
Yes
Check if the liquid
valve and gas
valve of outdoor
unit open
completely
Yes
Check if there is
leakage in the
pipeline
Yes
Weld the leakage point and
recharge refrigerant after
vacuum pumping and pressure
retaining are passed
Charge
refrigerant
according to the
No
requirement and
then turn on the unit
to see if E3
protection still
occurs
Completely open the liquid
No
valve and gas valve of outdoor
unit
Reconnect wire according to
the circuit diagram or replace
the pressure switch
U-Match Series DC
Inverter Service Manual
Enter
debugging mode
through wired
controller and select
Yes
without refrigerant
lacking protection; then
turn on the unit to see
if E3 protection still
occurs
Yes
09K~42K outdoor units
are without low pressure switch and
No
check if the wiring of mainboard is
normal; 48K~60K outdoor units are
with low pressure switch and
check if the low pressure
switch and its wiring
are normal
Yes
Replace the outdoor main
control board
83