
53
TROUBLESHOOTING (cont.)
Condition
Checking Area
Possible
Cause
Remedy
Self-
Diagnostic
Codes
(Wall
mounted
controller)
Buzzer
Pattern
Unit
does
not
operate
at all.
LCD
displays
self-
diagnostic
codes.
AL
1
Signal is input to
the fire alarm
connection.
Check the fire alarm
signal connection.
(See “Fire Alarm
Connection (Input
Signal) on page 34”.)
To reset: Press
RESET button.
PU
3
Drain hose clogged
(for internal drain
pump).
Check drain hose for
any blockages or
excessive kinks that
may prevent water
flow.
To reset: Press
RESET button.
Drain hose trap
position is too high
to pump up
condensation water
(for internal drain
pump).
Improve hose
installation.
To reset: Press
RESET button.
Internal drain pump
is not working.
Check the internal
drain pump
connection.
Replace drain pump.
To reset: Press
RESET button.
Summary of Contents for CM 25
Page 3: ...OPERATION MANUAL CM25...