Mitsubishi Electric PUHZ-RP3VHA Technical & Service Manual page 38

Phenomena
7. Remote controller display works
normally and the unit performs
heating operation, however, the
capacity cannot be fully obtained.
8. 1For 3 minutes after temperature
adjuster turns off, the compressor
will not start operating even if
temperature adjuster is turned on.
2For 3 minutes after temperature
adjuster turns on, the compressor
will not stop operating even if
temperature adjuster is turned off.
(Compressor stops operating
immediately when turning off by
the remote controller.)
Factor
1Linear expansion valve fault
Opening cannot be adjusted well due to linear expan-
sion valve fault.
2Refrigerant shortage
3Lack of insulation for refrigerant piping
4Filter clogging
5Heat exchanger clogging
6Air duct short cycle
7Bypass circuit of outdoor unit fault
12Normal operation
(For protection of compressor)
1• Discharging temperature and indoor
heat exchanger temperature does not
rise.
Inspect the failure by checking discharg-
ing pressure.
• Replace linear expansion valve.
2• If refrigerant leaks, discharging tempera
ture rises and LEV opening increases.
Inspect leakage by checking the tem-
perature and opening.
• Check pipe connections for gas leakage.
3Check the insulation.
4Open suction grill and check the filter.
Clean the filter by removing dirt or dust on
it.
5• If the filter is clogged, indoor pipe tem-
perature rises and discharging pressure
increases. Check if heat exchanger is
clogged by inspecting discharging pres-
sure.
• Clean the heat exchanger.
6Remove the shield.
7Check refrigerant system during opera-
tion.
12Normal operation
38
Countermeasure