MCQUAY Service Guide Book Diagnosis
48
Ceiling Exposed D Series Model
Model Board Handset
MCM 20/25/30/40/50D/DR U1.5 G7 / SLM3 / Netware 3 / SLM8
COOL
(Green)
DRY
(Orange)
FAN
(Green)
HEAT
(Red)
Error Code
(SLM3 /
Netware 3)
Operation / Faulty
Indication
Action
- Cooling mode -
- Dry mode -
- Fan mode -
- Heating mode -
-
Auto mode in
cooling operation
-
-
Auto mode in
heating operation
-
Heat LED
blinking
(SLM3 only)
Defrost mode -
E1
Room air sensor
contact loose / short
Check room sensor
connection / change room
sensor
E2
Indoor coil sensor
contact open / short
Check indoor coil sensor
connection / change indoor
coil sensor
E3
Outdoor coil sensor
contact open / short
Check outdoor coil sensor
connection / change
outdoor coil sensor
E4
Compressor
overload protection
If running ampere highly
increase, change the
compressor
E5 Gas leak
Check for leakage & repair /
Top up refrigerant