Fujitsu AB12 Service Manual page 95

ERROR
ERROR
CODE
21 Parallel commu- 1. Generation condition.
nication error
2. Corresponding operation.
1) Current operation continued,
2) If error continues for 90
3. Reset condition.
32 Outdoor unit
Error generated at outdoor unit
error
in same refrigerant system.
CONTENTS
Communication between
indoor unit control PC board
and indoor unit
communication PC board
not performed normally.
error display to standard
wired remote controller, and
display to indoor unit LED.
seconds after generation,
a new transmission error
(1F) is output.
Normal communication
restored between indoor unit
control PC and indoor unit
communication PC board.
ERROR CAUSE
1. Effect of extraneous noise.
2. Indoor unit communication
board insertion faulty.
3. PC board faulty.
Outdoor unit faulty.
– 95 –
REMEDY
1. When power turned off, then turned
back on:
1) If error not generated again, PC board
is normal. Therefore, remove noise
sources near indoor unit.
2) If error generated again, check
following, in addition to removing noise
sources.
2. Check indoor communication PC
board insertion.
3. Replace PC boards in following order,
and check operation.
(1) Indoor unit communication PC board.
(2) Indoor unit control PC board.
See "Outdoor unit troubleshooting".