MXZ-SM36NAMHZ Service Manual
69
OCH789
Check code
1501
(U2)
Closed valve in cooling mode
Abnormal points and detection methods Causes and checkpoints
If stop valve is closed during cooling operation.
When both of the following temperature conditions have been satised for
20 minutes or more during cooling operation.
1. TH22j − TH21j
]
−3.6°F [−2°C]
2. TH23j − TH21j
]
−3.6°F [−2°C]
Note:
For indoor unit, the abnormality is detected if an operating unit satises the
condition.
Outdoor liquid/gas valve is closed.
Mulfunction of outdoor LEV (LEV-A) (blockage)
TH21:
Indoor intake temperature thermistor
TH22:
Indoor liquid pipe temperature thermistor
LEV: Linear expansion valve
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis Remedy
v
Is the
outdoor stop valve
(liquid/gas)
fully open?
Open the
outdoor stop valve
(liquid/gas) fully
.
No
Yes
Disconnect the outdoor LEV wiring to
check the resistance.
No
Yes
Replace the outdoor LEV.
Replace the outdoor controller board.
Is the resistance detected?