Lennox Mini-Split Service Manual / Page 191
P5 Flow Chart
High temperature protection of
condenser
Check whether the compres-
sor temperature is higher than
149°F/65°C ?
Is the connection be-
tween the temperature
sensor and the PCB
correct?
No
Repair/replace wiring as
per wiring diagram.
No
Yes
Check the resistance
value of the outdoor
temperature sensor is
correct. Refer to table
Appendix 1.
Replace the temperature
sensor.
No
Yes
Yes
Check whether the outdoor ambi-
ent temperature is higher than
122°F/50°C.
Switch unit off until ambient tem-
perature is within normal operating
parameters.
Yes
No
Is there suffi cient airfl ow across
outdoor unit coils?
Remove obstruction or increase
ventilation path/airfl ow.
No
Remove remaining refrigerant
charge, pressure test and locate
leak. Add correct charge. Test
system. If system fails to operate
correctly replace outdoor board.
Replace the outdoor main board.
Yes
Are the outdoor unit fans operat-
ing correctly?
Refer to the fault code fan speed
malfunction (E8).
No
Yes
Are the outdoor unit coils clean?
Clean the outdoor coil thoroughly.
No
Yes
Confi rm if system has the correct
refrigerant charge.
No
Yes
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