Check code
1501
(U2)
Refrigerant shortage trouble
Abnormal points and detection methods
Causes and checkpoints
(1) Abnormal when all of the following conditions have been satisfied for
15 consecutive minutes:
1. The compressor is operating in HEAT mode.
2. Discharge superheat is 80
:
[144
_
F] or more.
3. Difference between TH7 and TH3 applies to the formula of
(TH7−TH3 < 5
:
[9
_
F])
4. The saturation temperature converted from a high pressure sensor
detects below 35
:
[95
_
F].
(2) Abnormal when all of the following conditions have been satisfied:
1. The compressor is in operation.
2. When cooling, discharge superheat is 80
:
[144
_
F] or more, and
the saturation temperature converted from a high pressure sensor is
over −40
:
[−40
_
F].
3. When heating, discharge superheat is 90
:
[162
_
F] or more.
Defective operation of stop valve (not fully open)
Defective thermistor
Defective outdoor multi controller circuit board
Indoor LEV performance failure
Gas leakage or shortage
Defective 63HS
TH3 : Thermistor <Outdoor liquid pipe>
TH7 : Thermistor <Ambient>
LEV : Linear expansion valve
63HS : High pressure sensor
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis
Remedy
Chart 1 of 2
Yes
No
No
No
No
Yes
Yes
Yes
Is the outdoor stop valve (ball
valve) fully open?
Is there a refrigerant leak?
Is 5104 displayed when restarted?
Is there any abnormality on
connectors such as a disconnection,
half-disconnection or breakage?
Refer to the diagnosis of check code 5104.
Check relevant thermistor wirings and
connector contacts of the outdoor multi
controller circuit board.
Disconnect the thermistor wiring and check
the resistance.
Open the stop valve (ball valve) fully.
Repair the refrigerant leak.
Connect the connector properly
(Repair or replace it in case of a breakage).
(leaking)
(5104)
(no leaking)
(1501)
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OCH668B
