9-5. How To Diagnose Faulty Parts
[08 Four-way valve error] (Heat pump model)
[04 Serial signal error] (Heat pump model)
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
Does outdoor
unit operate?
Are 1, 2 and 3 crossover
wires connected properly?
Is connector
connected properly?
Does LED (Orange) on
outdoor P.C. board blink?
Does LED (Green) on
outdoor P.C. board blink?
Outdoor P.C. board
is defective.
Replace
P.C. board.
Connect crossover
wires properly.
Connect connector
properly.
Indoor P.C. board
is defective.
Replace
P.C. board.
Operation
Check item
Conceivable principle cause
Measure
Item by symptoms
Does four-way valve
operate properly?
Does coil terminal
have 220
−
240 V
in heating operation?
Are circuit
wires normal?
Is outdoor P.C. board
normal?
Four-way valve
is defective.
Outdoor P.C. board
is defective.
(CN11 220
−
240 V)
Indoor P.C. board
is defective.
Replace
Four-way valve
Circuit check/modification
Replace
P.C. board.
Replace
P.C. board.
Replace TC sensor.
NO
NO
NO
YES
YES
YES
YES
YES
YES
NO
Is TC sensor
resistance value
(10 k
Ω
at 25
°
C) normal?
–
50
−
FILE NO. SVM-10049