MCQUAY Service Guide Book Diagnosis
57
Ceiling Convertible E Series Inverter-X Model
Model Board Handset
MCMX 15/20/25E/ER VA3.0 G17 / SLM3
COOL
(Green)
DRY
(Orange)
FAN
(Green)
HEAT
(Red)
Error
Code
(SLM3)
Operation / Faulty
Indication
Action
- Cooling mode -
- Dry mode -
- Fan mode -
- Heating mode -
- Defrost mode -
E1
Indoor temperature
sensor loose / short
Check indoor coil sensor
connection / change indoor
coil sensor
E2
Outdoor
temperature sensor
loose / short
Check outdoor coil sensor
connection / change outdoor
coil sensor
E3
Communication
error
Check connection wires
between indoor and outdoor
E4
Compressor
overload protection
If running ampere highly
increase, change the
compressor
E6
Compressor
overheat / gas leak
Check for leakage & repair /
Top up refrigerant
E7
IPM / PFC / Partial
switching
Check supply voltage and
compressor phase
E8 Outdoor over current
Check the input current and
discharge pressure