Mitsubishi Electric PKH18FK3 Technical & Service Manual page 31

(4) Detecting abnormalities in the outdoor unit
After the compressor has been continuously operated for 3 minutes, if the difference between the indoor coil temperature
and room temperature is out of RANGE C for 1 minute, the indoor fan speed will turn to LOW. Five minutes later, if the dif-
ference is still out of RANGE C,the outdoor unit is functioning abnormally. Thus, the compressor stops and check code
"P8" appears on remote controller.
RANGE A : Indoor coil temperature is more than 9 degrees above room temperature.
RANGE B : Indoor coil temperature is within 9 degrees either way of room temperature.
RANGE C : Indoor coil temperature is more than 9 degrees below room temperature.
Indoor coil temperature
minus room temperature
RANGE A
(degree)
+9
0 RANGE B
-9
RANGE C
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