Johnson Controls YVAHP072B31S, Service Manual

Page: 1439 / 1796

Service Manual
3-125
TROUBLESHOOTING
*1): For CIW01, refer to Section 3.1.4 (3).
*2): Refer to Section 3.1.4 (2).
Abnormalities of Devices
Other
Abnormalities
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Check thermistor in
self-checking mode *2).
Replace or correctly
connect wires
if abnormal.
Check it in
self-checking mode *1).
Check it in
self-checking mode *1).
Failure of
Discharge
Air Temp.
Thermistor
Failure of
Thermistor
Indoor Fan
Speed is
Not Changed
No Defrosting
Operation Mode
is Available
while Heating
Operation or
Defrosting
Operation is
Continued
Light and
LCD Indication
on Wired Zone
Controller
are Kept ON
Disconnected
Wire of
Thermistor
Failure of
Thermistor
for Outdoor
Evaporating
Temp. during
Heating
Failure of
Thermistor
Replace or correctly
connect it if abnormal.
Replace wired
controller if faulty.
Replace PCB if faulty.
Disconnected
Wire of
Thermistor
Measure resistance
of coil.
Failure of
Reversing
Valve
Disconnected
Reversing
Valve Coil
Supply power forcibly.
Replace reversing valve.
Incorrect
Activation of
Reversing
Valve
Check connectors.
Failure of
Outdoor Unit
PCB
Disconnected
Wire to PCB Correctly connect
wires.
Replace it when check
mode is not available. Failure of
PCB
Check PCB in
self-checking mode *1).
Check connectors.
Failure of
Indoor Unit
PCB
Disconnected
Wire to PCB Correctly connect
wires.
Replace PCB if faulty.
Failure of
PCB
Failure of
Wired Zone Controller
Failure of
Indoor Unit PCB
Check connectors.
Correctly connect
wires.
Disconnected Control Wires
between Indoor Unit and
Outdoor Unit
Failure of PCB in Indoor Unit
or Wired Zone Controller
Check Thermistor in
Self-Checking mode *2).
Check it in
Self-Checking mode *1).
Check PCB in
Self-Checking mode *1).
Failure of PCB in Indoor Unit
or Wired Controller
Failure of
Wired Controller
Check it in
Self-Checking mode *1).