Troubleshooting - Lennox MCA Series User Manual

• Fan – This is for Fan only, no cooling.
To set (or change) the room temperature setting
(set point)
Press the up and down arrow buttons to adjust the setpoint.
Cool/Fan mode
1. Press the Mode button to select either Cool or Fan.
2. Adjust the temperature setpoint using up and down
arrow buttons (range 62°F – 86°F).
3. Press the Fan Speed button to select Auto, Low, Med,
or High fan speed.
NOTE: Temperature set point is not displayed in fan mode.
1. Press the Power button. An LED light on the indoor unit
displays.
2. Press the Mode button to select Dry.
3. Adjust the temperature set point using up and down
arrow buttons.
NOTE: Fan speed is not adjustable in dry mode. Using dry
mode will over shoot the set point by 6 - 8 degrees.
There is no humidity sensor.
Timer Operation
Timer ON and Timer OFF are used to turn on and turn off
the indoor unit at selected intervals.
Timer ON Operation
1. Press the Timer ON button. The Timer ON icon, the last
auto-on time, and "h" will display.
2. Press the Timer ON button again to set the amount
of time before the indoor unit begins operation. Each
press will increase the time in half hour increments until
10 hours, then the increment becomes one hour.
Timer OFF Operation
1. Press the Timer OFF button. The Timer OFF icon, the
last auto-off time, and "h" will display.
2. Press the Timer OFF button again to set the amount of
time before the indoor unit stops operation. Each press
will increase the time in half hour increments until 10
hours, then the increment becomes 1 hour.
Modify Timer ON/OFF settings
1. Press either the Timer ON button or the Timer OFF
button to modify that setting.
2. Use the up arrow and down arrow buttons to change the
timed operation intervals.
3. Set the timer to 0.0 to turn off timed operation.
Dry Mode

Troubleshooting

If any of the following faults codes appear on your indoor unit, please
contact your li censed professional HVAC installer (or equivalent) or a
service agency.
Table 4. Faults Codes Displayed on Indoor Unit
Code Description
E0 Indoor unit EEPROM error
E1 Communication error between indoor unit and outdoor
unit
E3 Indoor fan speed error
E4 Indoor return air temperature sensor error
E5 Indoor coil temperature sensor error
EC Low refrigerant
EE High water level alarm
F0
Outdoor current overload sensed
F1
Outdoor ambient temperature sensor error
F2
Outdoor coil temperature sensor error
F3 Compressor discharge temperature sensor error
F4 Outdoor unit EEPROM error
F5 Outdoor unit fan speed error
P0 Inverter module IPM error
P1 High or low voltage protection
P3 Outdoor unit low temperature lockout
P4 Compressor drive error
--
Mode conflict
P6
Compressor high-pressure or low-pressure switch
open
7