Lennox MLB Series User Manual

29
Adding Refrigerant for Longer Line Set
The outdoor unit is factory-charged with refrigerant.
Calculate the additional refrigerant required according to
the diameter and the length of the liquid pipe between the
outdoor unit and indoor unit connections.
Be sure to add the proper amount of additional refrigerant.
Failure to do so may result in reduced performance.
Table 10. Additional Refrigerant Charge
System Size
(KBtu)
Pipe Length
(feet / meters)
Amount of Refrigerant
to add
06 and 09 >25 (7.5) 0.161 oz/ft (15g/m)
12 >25 (7.5) 0.161 oz/ft (15g/m)
18 >25 (7.5) 0.161 oz/ft (15g/m)
24 >25 (7.5) 0.322 oz/ft (30g/m)
30 >25 (7.5) 0.322 oz/ft (30g/m)
Troubleshooting
Table 11. Indoor Unit Error and Status
Code Display
Display Type Information
dF Status Defrost
CL Status
Filter cleaning reminder(power on display for
15 seconds).
CL Status Active clean
CP Status Remote switched off.
FC Status Forced cooling.
FP Status Heating in room temperature under 8°C.
nF Status
Filter replacement reminder (power on display
for 15 seconds).
EC 07 Error
The outdoor fan speed is operating outside of
the normal range.
EC 51 Error Outdoor unit EEPROM parameter error.
EC 52 Error
Condenser coil temperature sensor T3 is in
open circuit or has short circuited.
Table 11. Indoor Unit Error and Status
Code Display
Display Type Information
EC 53 Error
Outdoor ambient temperature sensor T4 is in
open circuit or has short circuited.
EC 54 Error
Compressor discharge temperature sensor
TP is in open circuit or has short circuited.
EC 56 Error
Evaporator coil outlet temperature sensor
(T2B multi-zone) is in open circuit or has
short circuited (for free-match indoor units).
EH 00
EH 0A
Error Indoor unit EEPROM parameter error.
EH 03 Error
The indoor fan speed is operating outside of
the normal range.
EH 06
Error
Communication error between main control
board and display board.
EH 60 Error
Indoor room temperature sensor T1 is in open
circuit or has short circuited.
EH 61 Error
Evaporator coil middle temperature sensor T2
is in open circuit or has short circuited.
EL 0C Error Refrigerant leakage detection.
PC 00 Error Inverter module IPM error.
PC 01 Error High or Low voltage protection.
PC 02 Error High temperature sensed at compressor top.
PC 03 Error Low or High pressure protection.
PC 04 Error Inverter compressor drive error.
PC 08 Error Current overload protection.
PC 0L Error Outdoor low ambient temperature protection.
-- Error
Indoor units mode conict (match with multi
outdoor unit).

Lennox MLB Series Specifications

General

Brand	Lennox
Model	MLB Series
Category	Indoor Furnishing
Language	English