SiUS30-1301
Troubleshooting by Indication on the Remote Controller
Service Diagnosis
229
3.45 Transmission Error between Indoor and Condensing Units
in the Same System
Error Code
U9
Applicable
Models
All indoor models
RWEYQ72P, 84P
Method of Error
Detection
Detect the error signal for the other indoor units within the circuit by condensing unit PCB.
Error Decision
Conditions
When the error decision is made on any other indoor unit within the system concerned.
Supposed
Causes
Transmission error within or condensing of other system
Defective electronic expansion valve in indoor unit of other system
Defective indoor unit PCB in other system
Improper connection of transmission wiring between indoor and condensing unit
Troubleshooting
All the
u
nits are
indicating “
U9
”.
“
U9
” has
b
een
displayed for 2 min
u
tes or
more.
Contin
u
e the operation.
N
O
Re-diagnose
b
y display after
passage of 2 min
u
tes or
more.
N
O
The condensing
u
nit PCB
indicated
b
y the error code
"
U9
" is normal.
Check for the indoor
u
nit of
other system, and then
cond
u
ct tro
ub
leshooting
b
y
diagnosis according to the
Error Code Flo
w
chart.
YES
YES
T
u
rn O
N
all indoor
u
nits.
Caution
Be s
u
re to t
u
rn off the po
w
er s
w
itch
b
efore connecting or disconnecting
connectors, or parts may
b
e damaged.