Daikin AT12BV1LS Pocket Manual page 154

Si10-417
Service Diagnosis
Valve Body Condition
(Symptom)
(1) Valve body catches
at fully opened or half
opened position.
(Symptom)
Cooling:
Water leakage at the
no-operation unit
Flow noise of
refrigerant in the no-
operation unit
Operation halt due to
icing protection
Heating:
The unit does not
heat
Refrigerant flow rate
vary by unit
(Discharge air
temperatures are
different by room)
Peak cut
(2) Valve body catches
at complete close
position.
(Symptom)
Cooling:
The only unit having
problem does not cool
the room .
When the only faulty
unit is in operation, the
unit makes pump
down.
(The low pressure of
the unit becomes
vacuum)
IT is activated.
Abnormal discharge
pipe temperature
Heating:
Insufficient gas due to
liquid refrigerant
stagnation inside
the faulty indoor unit
(Only for heat pump
model)
The unit does not
heat the room.
IT is activated.
Abnormal discharge
pipe temperature
Troubleshooting
Check Method / Measure
Reset power supply and
conduct cooling operation unit
by unit
.
Check the liquid pipe
temperature of no-
operation unit.
Is it almost
same as the outside
air temperature?
YES
Replace the EVn of the room.
Reset power supply and
conduct cooling operation unit
by unit
.
Check the low pressure
Does the
pressure become into
vacuum zone?
YES
Replace the EVn of the room.
NO
(R1431)
NO
(R1432)
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