Page 1 LENNOX MINI-SPLIT SYSTEMS SERVICE MANUAL Lennox Mini-Split Service Manual / Page 1...
Page 2 Publication No. 450510 Origination date - 11/2015 ©2015 Lennox Industries Inc. Lennox Mini-Split Service Manual / Page 2...
Page 3: Table Of Contents
SPECIFICATIONS - CEILING/FLOOR MOUNT INDOOR UNITS - 036-048 ....38 SECTION 3 - INSTALLATION DIMENSIONS OF OUTDOOR UNITS ........39 SECTION 3.1 - SINGLE ZONE INSTALLATION DIMENSIONS ..........40 MPA009S4S, MPA012S4S, MPA018S4S Dimensions ...........41 MPA024S4S, MPA030S4S, MPA036S4S Dimensions ...........42 MPA048S4S Dimensions ....................43 Lennox Mini-Split Service Manual / Page 3...
Page 4 036 & 048 SIZES ONLY ......................86 SECTION 9 - WIRING DIAGRAMS ..................87 SECTION 9.1 - SINGLE ZONE WIRING DIAGRAMS ............88 115V MPA009S4S-1L and MPA012S4S-1L Outdoor Unit Wiring Diagram ....89 208/230V MPA009S4S-1P and MPA012S4S-1P Outdoor Unit Wiring Diagram ..89 208/230 MPA018S4S-1P Outdoor Unit Wiring Diagram ..............90...
Page 5 SECTION 11.2 - M0STAT61Q-1 WIRED CONTROLLER ............117 SECTION 12 - START UP ....................119 SECTION 12.1 - GENERAL START UP INFORMATION ............120 Outdoor Unit Spot Check Function ................121 Outdoor unit’s digital display tube ................125 Lennox Mini-Split Service Manual / Page 5...
Page 6 P2 Flow Chart ........................183 P3 Fault Code ........................185 P3 Flow Chart ........................186 P4 Fault Code ........................188 P4 Flow Chart ........................189 P5 Fault Code ........................190 P5 Flow Chart ........................191 P6 Fault Code ........................192 P6 Flowchart ........................193 Lennox Mini-Split Service Manual / Page 6...
Page 7 Appendix 1 ........................241 Temperature Sensor Resistance Value Table (°C--K) ..........241 Appendix 2 ........................242 Discharge Temperature Sensor Table (°C--K) ..............242 Appendix 3 ........................243 Celsius to Fahrenheit Conversion Table ..............243 Compressor Check ......................244 IPM Check ........................245 Lennox Mini-Split Service Manual / Page 7...
Page 8 Electronic Control Working Environment ..............252 Main Protection ......................252 Compressor Preheating Functions ................253 Compressor Crankcase Heater ..................253 Capacity Request Calculation ..................254 Defrost Control ......................256 Outdoor Fan Control .....................257 Four-Way Valve Control ....................258 Electronic Expansion Valve (EXV) Control ..............258 Lennox Mini-Split Service Manual / Page 8...
Page 9: Section 1 - Outdoor Unit Data
SECTION 1 - OUTDOOR UNIT DATA Lennox Mini-Split Service Manual / Page 9...
Page 10: Section 1.1 - Mpa Single Zone Condensing Units
SECTION 1.1 - MPA SINGLE ZONE CONDENSING UNITS Lennox Mini-Split Service Manual / Page 10...
Page 11: Model Number Identification
B = 2nd Generation Nominal Cooling Capacity Refrigerant Type 018 = 1.5 tons 4 = R-410A 030 = 2.5 tons 036 = 3 tons 048 = 4 tons Cooling Efﬁ ciency S = Standard Efﬁ ciency Lennox Mini-Split Service Manual / Page 11...
Page 12: Specifications - 0.75 - 1 Ton Mpa Outdoor Units - 115V-1 Phase
NOTE - Extremes of operating range are plus and minus 10% of line voltage. HACR type circuit breaker or fuse. Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Lennox Mini-Split Service Manual / Page 12...
Page 13: Specifications - 0.75 - 1.5 Ton Mpa Outdoor Units - 208/230V-1 Phase
NOTE - Extremes of operating range are plus and minus 10% of line voltage. HACR type circuit breaker or fuse. Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Lennox Mini-Split Service Manual / Page 13...
Page 14: Specifications - 2 - 4 Ton Mpa Outdoor Units - 208/230V-1 Phase
NOTE - Extremes of operating range are plus and minus 10% of line voltage. HACR type circuit breaker or fuse. Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Lennox Mini-Split Service Manual / Page 14...
Page 15: Section 1.2 - Mpa Multi-Zone Condensing Unit
SECTION 1.2 - MPA MULTI-ZONE CONDENSING UNIT Lennox Mini-Split Service Manual / Page 15...
Page 16: Specifications - 1.5 - 2.5 Ton Mpa Outdoor Units
Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. NOTE - Adaptors are furnished for the gas pipe connections: 018 - (2) 3/8 x 1/2 in. 030 - (3) 3/8 x 1/2 in. Lennox Mini-Split Service Manual / Page 16...
Page 17: Specifications - 3 - 4 Ton Mpa Outdoor Units
036 - (3) 3/8 x 1/2 in. and (1) 1/2 x 3/8 in. 048 - (3) 3/8 x 1/2 in., (2) 1/2 x 3/8 in., (2) 1/4 x 3/8 in. and (2) 1/2 x 5/8 in. Lennox Mini-Split Service Manual / Page 17...
Page 18: Section 2 - Indoor Unit Data
SECTION 2 - INDOOR UNIT DATA Lennox Mini-Split Service Manual / Page 18...
Page 19: Section 2.1 - M22A Compact Cassette Unit
SECTION 2.1 - M22A COMPACT CASSETTE UNIT Lennox Mini-Split Service Manual / Page 19...
Page 20: Model Number Identification
Nominal Cooling Capacity Cooling Efﬁ ciency 009 = .75 tons S = Standard Efﬁ ciency 012 = 1 tons 018 = 1.5 tons 024 = 2 tons 036 = 3 tons 048 = 4 tons Lennox Mini-Split Service Manual / Page 20...
Page 21: Specifications - Cassette Indoor Units - M22A009-018
36 / 42 36 / 42 40 / 47 REQUIRED COMPONENTS - ORDERED SEPARATELY Cassette Panel 13X04 (M0STAT62Q-1) 13X04 (M0STAT62Q-1) 13X04 (M0STAT62Q-1) Net/Shipping weights - lbs. 6 / 10 6 / 10 6 / 10 Lennox Mini-Split Service Manual / Page 21...
Page 22: Sound Data
SOUND DATA Lennox Mini-Split Service Manual / Page 22...
Page 23: Air Throw Data
AIR THROW DATA Lennox Mini-Split Service Manual / Page 23...
Page 24: Section 2.2 - M33A Cassette Unit
SECTION 2.2 - M33A CASSETTE UNIT Lennox Mini-Split Service Manual / Page 24...
Page 25: Model Number Identification
Nominal Cooling Capacity Cooling Efﬁ ciency 009 = .75 tons S = Standard Efﬁ ciency 012 = 1 tons 018 = 1.5 tons 024 = 2 tons 036 = 3 tons 048 = 4 tons Lennox Mini-Split Service Manual / Page 25...
Page 26: Specifications - Cassette Indoor Units - M33A024-048
46 / 53 56 / 63 64 / 74 REQUIRED COMPONENTS - ORDERED SEPARATELY Cassette Panel 13X05 (M0STAT63Q-1) 13X05 (M0STAT63Q-1) 13X05 (M0STAT63Q-1) Net/Shipping weights - lbs. 12 / 18 12 / 18 12 / 18 Lennox Mini-Split Service Manual / Page 26...
Page 27: Section 2.3 - Mmda Ducted Unit
SECTION 2.3 - MMDA DUCTED UNIT Lennox Mini-Split Service Manual / Page 27...
Page 28: Model Number Identification
Nominal Cooling Capacity Cooling Efﬁ ciency 009 = .75 tons S = Standard Efﬁ ciency 012 = 1 tons 018 = 1.5 tons 024 = 2 tons 036 = 3 tons 048 = 4 tons Lennox Mini-Split Service Manual / Page 28...
Page 29: Specifications - Medium Static Ducted Indoor Units - 009-018
Piping Connections - Liquid/Gas - o.d. - ﬂ are - in. 3/8 / 5/8 3/8 / 5/8 3/8 / 5/8 Drain connection o.d. - in. Net/Shipping weights - lbs. 58 / 69 78 / 93 100 / 117 Lennox Mini-Split Service Manual / Page 29...
Page 30: Blower Data
0.16 0.08 0.12 0.14 0.12 0.10 0.06 0.10 0.08 0.08 0.04 0.06 0.06 0.04 0.04 0.02 0.02 0.02 0.00 0.00 0.00 Air Volume - cfm Air Volume - cfm Air Volume - cfm Lennox Mini-Split Service Manual / Page 30...
Page 31 0.15 0.15 0.15 0.10 0.10 0.10 0.05 0.05 0.05 0.00 0.00 0.00 1000 1100 1200 1000 1100 1200 1300 1000 1200 Air Volume - cfm Air Volume - cfm Air Volume - cfm Lennox Mini-Split Service Manual / Page 31...
Page 32 0.15 0.10 0.10 0.10 0.05 0.05 0.05 0.00 0.00 0.00 1100 1300 1500 1100 1300 1500 1700 1100 1300 1500 1700 Air Volume - cfm Air Volume - cfm Air Volume - cfm Lennox Mini-Split Service Manual / Page 32...
Page 33: Section 2.4 - Mwma Wall Mounted Unit
SECTION 2.4 - MWMA WALL MOUNTED UNIT Lennox Mini-Split Service Manual / Page 33...
Page 34: Model Number Identification
4 = R-410A Nominal Cooling Capacity 009 = .75 tons 012 = 1 tons 018 = 1.5 tons Cooling Efﬁ ciency 024 = 2 tons S = Standard Efﬁ ciency 030 = 2.5 tons Lennox Mini-Split Service Manual / Page 34...
Page 35: Specifications - Wall-Mounted Indoor Units - 009-012
1/4 / 1/2 3/8 / 5/8 3/8 / 5/8 Drain connection o.d. - in. Total refrigerant pipe length - ft. Net/Shipping weights - lbs. 27 / 35 40 / 51 40 / 51 Lennox Mini-Split Service Manual / Page 35...
Page 36: Section 2.5 - Mcfa Ceiling/Floor Unit
SECTION 2.5 - MCFA CEILING/FLOOR UNIT Lennox Mini-Split Service Manual / Page 36...
Page 37: Model Number Identification
B = 2nd Generation Nominal Cooling Capacity Cooling Efﬁ ciency 012 = 1 tons S = Standard Efﬁ ciency 018 = 1.5 tons 024 = 2 tons 036 = 3 tons 048 = 4 tons Lennox Mini-Split Service Manual / Page 37...
Page 38: Specifications - Ceiling/Floor Mount Indoor Units - 012-024
52/54/57 Piping Connections - Liquid/Gas - o.d. - ﬂ are - in. 3/8 / 5/8 3/8 / 5/8 Drain connection o.d. - in. Net/Shipping weights - lbs. 67 / 78 84 / 97 Lennox Mini-Split Service Manual / Page 38...
Page 39: Section 3 - Installation Dimensions Of Outdoor Units
SECTION 3 - INSTALLATION DIMENSIONS OF OUTDOOR UNITS Lennox Mini-Split Service Manual / Page 39...
Page 40: Section 3.1 - Single Zone Installation Dimensions
SECTION 3.1 - SINGLE ZONE INSTALLATION DIMENSIONS Lennox Mini-Split Service Manual / Page 40...
Page 41: Mpa009S4S, Mpa012S4S, Mpa018S4S Dimensions
MPA009S4S, MPA012S4S, MPA018S4S Dimensions (559) FRONT VIEW SIDE VIEW 2-1/2 (64) 31-7/8 (809) 21-5/8 (549) TOP VIEW 27-1/2 (699) FRONT VIEW SIDE VIEW 33-1/4 (845) 2-7/8 (73) 22 (559) TOP VIEW Lennox Mini-Split Service Manual / Page 41...
Page 42: Mpa024S4S, Mpa030S4S, Mpa036S4S Dimensions
MPA024S4S, MPA030S4S, MPA036S4S Dimensions 31-7/8 (810) SIDE VIEW FRONT VIEW 37-1/4 (946) 3-3/8 (86) 25-1/4 (641) 15-1/2 (394) TOP VIEW Lennox Mini-Split Service Manual / Page 42...
Page 43: Mpa048S4S Dimensions
MPA048S4S Dimensions 25 (635) 15-3/8 14-1/2 (391) (369) (406) 36-7/8 (937) 3-3/8 (86) TOP VIEW 53-3/4 (1365) SIDE VIEW FRONT VIEW SIDE VIEW BOTTOM VIEW Lennox Mini-Split Service Manual / Page 43...
Page 44: Section 3.2 - Multi-Zone Installation Dimensions
SECTION 3.2 - MULTI-ZONE INSTALLATION DIMENSIONS Lennox Mini-Split Service Manual / Page 44...
Page 45: Mpa018S4M Dimensions
Dimensions MPA018S4M MPA018S4M 12-3/4 12-1/4 13-1/8 14-1/8 (324) (312) (333) (359) 22 (559) TOP VIEW 27-3/8 (695) 33-1/8 (841) 2-3/4 (70) FRONT VIEW SIDE VIEW Lennox Mini-Split Service Manual / Page 45...
Page 46: Mpa030S4M, Mpa036S4M Dimensions
Dimensions MPA030S4M, MPA036S4M 31-7/8 (810) SIDE VIEW FRONT VIEW 37-1/4 (946) 3-3/8 (86) 25-1/4 (641) 15-1/2 (394) TOP VIEW Lennox Mini-Split Service Manual / Page 46...
Page 47: Mpa048S4M Dimensions
Dimensions MPA048S4M 25 (635) 15-3/8 14-1/2 (391) (369) (406) 36-7/8 (937) 3-3/8 (86) TOP VIEW 53-3/4 (1365) SIDE VIEW FRONT VIEW SIDE VIEW BOTTOM VIEW Lennox Mini-Split Service Manual / Page 47...
Page 48: Section 3.3 - Mpa Outdoor Unit Clearances
SECTION 3.3 - MPA OUTDOOR UNIT CLEARANCES Lennox Mini-Split Service Manual / Page 48...
Page 49: Outdoor Unit Clearances
2007 Clearance dimensions apply to both single-fan cabinets and double-fan cabinets. Minimum rear clearance can be 6 inches (152 mm) when mounted on brackets and with no obstructions on the other three sides. Lennox Mini-Split Service Manual / Page 49...
Page 50: Section 4 - Installation Dimensions Of Indoor Units
SECTION 4 - INSTALLATION DIMENSIONS OF INDOOR UNITS Lennox Mini-Split Service Manual / Page 50...
Page 51: Section 4.1 - M22A Compact Cassette
SECTION 4.1 - M22A COMPACT CASSETTE Lennox Mini-Split Service Manual / Page 51...
Page 52 RIGHT SIDE VIEW 22-1/2 (572) BOTTOM VIEW (Body) INSTALLATION HANGERS LEVELING ADJUSTMENT NUT (4) CEILING OUTLET OUTLET DIFFUSER INLET PANEL 23-5/8 (600) (Ceiling Opening) SIDE VIEW 25-1/2 (648) 25-1/2 (648) BOTTOM VIEW (Panel) Lennox Mini-Split Service Manual / Page 52...
Page 53 (914 mm) 36” 36” (914 mm) (914 mm) 36” (914 mm) Minimum Clearance from Structural Ceiling to Drop Ceiling: M22A009, M22A012, M22A018 -- 10-1/4” (260 mm) Minimum Clearance to Floor - 98-1/2” (2500 mm) Lennox Mini-Split Service Manual / Page 53...
Page 54: Section 4.2 - M33A Cassette Unit
SECTION 4.2 - M33A CASSETTE UNIT Lennox Mini-Split Service Manual / Page 54...
Page 55 PIPE LIQUID PIPE 30-3/4 (781) 33-1/8 (841) DRAIN CONNECTION RIGHT SIDE VIEW 26-3/4 (679) 33-1/8 (841) BOTTOM VIEW (Body) OUTLET OUTLET DIFFUSER INLET PANEL SIDE VIEW 37-3/8 (949) 37-3/8 (949) BOTTOM VIEW (Panel) Lennox Mini-Split Service Manual / Page 55...
Page 56 (914 mm) (914 mm) 36” (914 mm) Minimum Clearance from Structural Ceiling to Drop Ceiling: M33A024 -- 10-1/4” (260 mm) M33A036, M33A048 -- 13” (330 mm) Minimum Clearance to Floor - 98-1/2” (2500 mm) Lennox Mini-Split Service Manual / Page 56...
Page 57: Section 4.3 - Mmda Ducted Unit
SECTION 4.3 - MMDA DUCTED UNIT Lennox Mini-Split Service Manual / Page 57...
Page 58 38-1/8 968 1-1/2 Size 009 thru 012 4-5/8 23-1/2 7-7/8 3-1/8 29-1/8 13-3/4 4-5/8 7-7/8 3-1/8 37-3/4 13-3/4 10-1/4 37-3/4 13-3/4 40-3/4 1035 10-1/4 46-1/2 1181 19-1/4 1092 11-3/8 1-3/4 48-7/8 1241 19-5/8 Lennox Mini-Split Service Manual / Page 58...
Page 59 MMDA Indoor Units Clearances Wall 20” (508) Minimum Service Clearance DUCTED UNIT Flow 24” (610) Minimum Service Clearance Wall 24” (610) Minimum Service Clearance TOP VIEW Ceiling 1” (25 mm) Minimum Clearance SIDE VIEW Lennox Mini-Split Service Manual / Page 59...
Page 60: Section 4.4 - Mwma Wall Mounted Unit
SECTION 4.4 - MWMA WALL MOUNTED UNIT Lennox Mini-Split Service Manual / Page 60...
Page 61 MWMA Indoor Units Dimensions MWMA009SA, MWMA012S4, MWMA018SA, MWMA024S4, MWMA030S4 TOP VIEW SIDE VIEW SIDE VIEW BOTTOM VIEW Size 009, 012 32-7/8 29-1/4 7-7/8 12-3/8 34-3/4 8-5/8 024, 030 46-3/4 1187 13-1/2 42-1/2 1080 10-1/4 Lennox Mini-Split Service Manual / Page 61...
Page 62 6” (152 mm) Minimum Clearance Wall Wall 5” 5” (127 mm) (127 mm) Minimum Minimum Vertical Clearance - Clearance to Floor - 72 inches (1829 mm) Minimum 96 inches (2438 mm) Recommended Floor FRONT VIEW Lennox Mini-Split Service Manual / Page 62...
Page 63: Section 4.5 - Mcfa Ceiling/Floor Unit
SECTION 4.5 - MCFA CEILING/FLOOR UNIT Lennox Mini-Split Service Manual / Page 63...
Page 64 2 (51) Piping 2-1/4 (57) Condensate Drain Refrigerant Outlets (2) each side BOTTOM VIEW Piping Opening 4-3/4 x 5-1/2 (121 x 140) Model No. 42-1/8 1070 50-5/8 1286 47-3/8 1203 1651 61-3/4 1568 Lennox Mini-Split Service Manual / Page 64...
Page 65 SIDE VIEW SUPPLY CEILING AND FLOOR APPLICATIONS WALL WALL 24” (610) (610) FRONT VIEW FLOOR APPLICATIONS Unit Flush with Wall SUPPLY 24” (610) (Service Clearance Front of Unit) 1” (25.4) FLOOR SIDE VIEW Lennox Mini-Split Service Manual / Page 65...
Page 66: Section 5 - Indoor Unit Combinations
SECTION 5 - INDOOR UNIT COMBINATIONS Lennox Mini-Split Service Manual / Page 66...
Page 67: Multi-Zone System Combinations
9,954 9,954 - - - One outdoor unit may be matched with one indoor unit for single zone applications. A second indoor unit can be added at a later date for multi-zone applications. Lennox Mini-Split Service Manual / Page 67...
Page 68 - - - - - - One outdoor unit may be matched with one indoor unit for single zone applications. A second indoor unit can be added at a later date for multi-zone applications. Lennox Mini-Split Service Manual / Page 68...
Page 69: Multi-Zone System Combinations
012 012 012 012 012 10,306 10,306 10,306 10,306 10,306 11,055 11,055 11,055 11,055 11,055 One outdoor unit may be matched with one indoor unit for single zone applications. A second indoor unit can be added at a later date for multi-zone applications. Lennox Mini-Split Service Manual / Page 69...
Page 70: Section 6 - Refrigeration Pipe Work
SECTION 6 - REFRIGERATION PIPE WORK Lennox Mini-Split Service Manual / Page 70...
Page 71: Section 6.1 - Single Zone Refrigerant Cycle Diagram
SECTION 6.1 - SINGLE ZONE REFRIGERANT CYCLE DIAGRAM Lennox Mini-Split Service Manual / Page 71...
Page 72 T3 Condenser temp. sensor Indoor Coil Outdoor Coil T4 Ambient T1 Room temp. temp. sensor sensor T2 Evaporator temp. sensor GAS SIDE 4-WAY VALVE 3-WAY VALVE Accumulator T5 Discharge temp. sensor COOLING Compressor HEATING Lennox Mini-Split Service Manual / Page 72...
Page 73: Section 6.2 - Multi-Zone Refrigerant Cycle Diagram
SECTION 6.2 - MULTI-ZONE REFRIGERANT CYCLE DIAGRAM Lennox Mini-Split Service Manual / Page 73...
Page 74 Two-Zone Refrigerant Cycle Diagram Lennox Mini-Split Service Manual / Page 74...
Page 75 Three-Zone Refrigerant Cycle Diagram Lennox Mini-Split Service Manual / Page 75...
Page 76 Four-Zone Refrigerant Cycle Diagram Lennox Mini-Split Service Manual / Page 76...
Page 77 Five-Zone Refrigerant Cycle Diagram Lennox Mini-Split Service Manual / Page 77...
Page 78: Section 6.1 - Refrigeration Pipe Work For Singe Zone Systems
SECTION 6.1 - REFRIGERATION PIPE WORK FOR SINGE ZONE SYSTEMS Lennox Mini-Split Service Manual / Page 78...
Page 79: Piping Limitations
82 ft. (25 m) 82 ft. (25 m) 164 ft. (50 m) 98 ft. (30 m) 98 ft. (30 m) 213 ft. (65 m) 98 ft. (30 m) 98 ft. (30 m) 213 ft. (65 m) Lennox Mini-Split Service Manual / Page 79...
Page 80: Section 6.2 - Refrigeration Pipe Work For Multi-Zone Systems
SECTION 6.2 - REFRIGERATION PIPE WORK FOR MULTI-ZONE SYSTEMS Lennox Mini-Split Service Manual / Page 80...
Page 81 Set Elevation 3-Zone 82 ft. (25 m) Indoor Units 4-Zone 98 ft. (30 m) Below Outdoor Unit INDOOR UNIT 4-Zone 98 ft. (30 m) 33 ft. (10 m) INDOOR UNIT Five-Zone System Example shown Lennox Mini-Split Service Manual / Page 81...
Page 82: Connections And Line Set Usage
1/2 x 5/8 in. gas pipe adaptor is required for line set connection to the 048 1/2 x 5/8 in. gas pipe adaptor is required for line set connection to the 048 outdoor unit (furnished with outdoor unit). outdoor unit (furnished with outdoor unit). Lennox Mini-Split Service Manual / Page 82...
Page 83: Connections And Line Set Usage
1/2 x 5/8 in. gas pipe adaptor is required for line set connection to the 048 1/2 x 5/8 in. gas pipe adaptor is required for line set connection to the 048 outdoor unit (furnished with outdoor unit). outdoor unit (furnished with outdoor unit). Lennox Mini-Split Service Manual / Page 83...
Page 84: Connections And Line Set Usage
(furnished with outdoor unit). outdoor unit (furnished with outdoor unit). 1/2 x 5/8 in. gas pipe adaptor is required for line set connection to the 048 outdoor unit (furnished with outdoor unit). Lennox Mini-Split Service Manual / Page 84...
Page 85: Section 7 - Power Wiring For Outdoor & Indoor Units
SECTION 7 - POWER WIRING FOR OUTDOOR & INDOOR UNITS Lennox Mini-Split Service Manual / Page 85...
Page 86: Section 8 - Data Wiring
SECTION 8 - DATA WIRING 036 & 048 SIZES ONLY Lennox Mini-Split Service Manual / Page 86...
Page 87: Section 9 - Wiring Diagrams
SECTION 9 - WIRING DIAGRAMS Lennox Mini-Split Service Manual / Page 87...
Page 88: Section 9.1 - Single Zone Wiring Diagrams
SECTION 9.1 - SINGLE ZONE WIRING DIAGRAMS Lennox Mini-Split Service Manual / Page 88...
Page 89: 115V Mpa009S4S-1L And Mpa012S4S-1L Outdoor Unit Wiring Diagram
115V MPA009S4S-1L and MPA012S4S-1L Outdoor Unit Wiring Diagram PAN HEATER CRANKCASE CN34 CN15 HEATER CN33 CN32 CN31 CN28 VALVE CN26 YELLOW BLUE BROWN BLUE L-A(CN37) CN10 POWER SUPPLY BLACK Typical wiring diagram. Refer BLACK 115V to wiring diagram on the unit for actual wiring.
Page 90: Vmpa018S4S-1P
208/230V MPA024S4S-1P Outdoor Unit Wiring Diagram Compressor L-OUT COMPRESSOR DISCHARGE Control Board TEMP.SENSOR CN10 YELLOW PAN HEATER CRANK CASE HEATER Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 90...
Page 91: 208/230V Mpa030S4S-1P Outdoor Unit Wiring Diagram
CRANKCASE HEATER L1 L2 H-PRO HIGH PRESSURE SWITCH L-PRO LOW PRESSURE SWITCH PFC INDUCTOR 4-WAY VALVE OUTDOOR COIL TEMP.SENSOR OUTDOOR TEMP.SENSOR Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 91...
Page 92: 208/230V Mpa036S4S-1P Outdoor Unit Wiring Diagram
P O W E R S U P P LY 4 WAY VALVE OUTDOOR COIL TEMP. SENSOR OUTDOOR TEMP. SENSOR Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 92...
Page 93: 208/230V Mpa048S4S-1P Outdoor Unit Wiring Diagram
DCFAN2 DCFAN1 NOTE Please use 2-core COMP shielded wire. BLUE CN17 4-WAY CN18 BLUE CN24 HEAT_Y CN25 CN19 HEAT_D CN20 Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 93...
Page 94: Section 9.1 - Multi-Zone Wiring Diagrams
SECTION 9.1 - MULTI-ZONE WIRING DIAGRAMS Lennox Mini-Split Service Manual / Page 94...
Page 95: 208/230V Mpa018S4M-1P Outdoor Unit Wiring Diagram
EXPANSION CN11 VALVE CN12 BLUE 1(A) 3(A) 2(A) 1(B) 2(B) 3(B) 1(C) 2(C) 3(C) 4 WAY CRANKCASE HEATER VALVE HEATER Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 95...
Page 96: Mpa036S4M-1P Outdoor Unit Wiring Diagram
C N 2 4 HEA T_Y C N 2 5 C N 1 9 HEA T_D C N 2 0 Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 96...
Page 97: Section 9.1 - Indoor Unit Wiring Diagrams
SECTION 9.1 - INDOOR UNIT WIRING DIAGRAMS Lennox Mini-Split Service Manual / Page 97...
Page 98: Mwma Unit Wiring Diagram
MWMA Unit Wiring Diagram CN10A CN3(CN301) CN501 Contoller CN403 OPTIONAL DISPLAY BOARD Wire Contoller Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. To CCM Comm.Bus Lennox Mini-Split Service Manual / Page 98...
Page 99: M22A009S4-1P, M22A012S4-1P, M22A018S4-1P, M33A024S4-1P Unit Wiring Diagram
WHITE CN13 MAINBOARD PUMP WATER LEVEL SWITCH CN110 E Y X Typical wiring diagram. Refer to wiring diagram on the unit for actual 1 2 3 wiring. To CCM Comm.Bus TO OUTDOOR UNIT Lennox Mini-Split Service Manual / Page 99...
Page 100: M33A036S4-1P & M33A048S4-1P Unit Wiring Diagram
INDOOR COIL OUTLET TEMP.SENSOR Reactor INDOOR COIL TEMP.SENSOR BLACK ROOM TEMP.SENSOR WHITE WATER LEVEL SWITCH Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. To CCM POWER Comm.Bus To OUTDOOR Comm.Bus Lennox Mini-Split Service Manual / Page 100...
Page 101: Mmda024S4-1P Ducted Units Wiring Diagram
INDOOR COIL OUTLET TEMP. SENSOR Typical wiring diagram. Refer to wiring diagram on WATER LEVEL SWITCH the unit for actual wiring. BLACK BLACK FILTER-BOARD To CCM To outdoor Comm.Bus Comm.Bus POW ER SUPPLY Lennox Mini-Split Service Manual / Page 101...
Page 102: Mmda009S4-1P, Mmda012S4-1P, Mmdaa018S4-1P Ducted Units Wiring Diagram
INDOOR COIL TEMP. SENSOR WHITE ROOM TEMP. SENSOR Typical wiring diagram. WATER LEVEL SWITCH Refer to wiring diagram on YELLOW the unit for actual wiring. BLACK BLACK FILT ER- B OA RD To CCM Comm.Bus Lennox Mini-Split Service Manual / Page 102...
Page 103: Mcfa024S4-1P Unit Wiring Diagram
BLACK FILTER-BOARD Ferrite bead Remote Alarm Control Output To CCM Comm.Bus • • • • • To outdoor This symbol indicates the element is Comm.Bus optional,the actual shape shall prevail. Lennox Mini-Split Service Manual / Page 103...
Page 104: Mcfa048S4-1P Unit Wiring Diagram
Comm.Bus • • • • • This symbol indicates the element is To outdoor Comm.Bus optional,the actual shape shall prevail. Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring. Lennox Mini-Split Service Manual / Page 104...
Page 105: Section 10 - Condensate Pipe Work Installation Data
SECTION 10 - CONDENSATE PIPE WORK INSTALLATION DATA Lennox Mini-Split Service Manual / Page 105...
Page 106: Section 10.1 - Outdoor Unit Condensate Pipe
SECTION 10.1 - OUTDOOR UNIT CONDENSATE PIPE Lennox Mini-Split Service Manual / Page 106...
Page 107: Condensate Piping Requirements - Outdoor Unit
1 inch (25 mm) drain holes and attached a ﬁ eld-provided insulated drain hose to the connector. Use ﬁ eld-provided rubber plugs to cover any unused drain holes. Condensate Drain Drain (location varies per model) Chassis Connector Lennox Mini-Split Service Manual / Page 107...
Page 108: Section 10.2 - Indoor Unit Gravity Drain
SECTION 10.2 - INDOOR UNIT GRAVITY DRAIN Lennox Mini-Split Service Manual / Page 108...
Page 109: Condensate Piping Requirements - Mwma & Mcfa
MAIN DRAIN (Sloped at 1/4” per foot AWAY from unit and should be supported as needed to prevent sagging.) Condensate Drain Multiple Indoor Units Suspended from Ceiling Using a Single Properly Sloped Gravity Drain Lennox Mini-Split Service Manual / Page 109...
Page 110: Section 10.3 - Indoor Unit Lift Pump
SECTION 10.3 - INDOOR UNIT LIFT PUMP Lennox Mini-Split Service Manual / Page 110...
Page 111: Condensate Piping Requirements - Mmda & M22A/M33A
(ground, open drain, etc.) to ensure that the line will drain freely. STRUCTURAL CEILING 8 in. 3 ft. (1 m) (203 mm) SUSPENSION RODS SUPPORT STRAPS DRAIN LINE Condensate Drain with Pump Lennox Mini-Split Service Manual / Page 111...
Page 112: M22A And M33A
7-7/8in. 2~3-15/16 in. 3 ft. (1 m) Cassette SUPPORT Unit STRAPS Drain (slope of at least ¼ inch per foot) Indoor Unit Condensate Drain Lennox Mini-Split Service Manual / Page 112...
Page 113: Section 11 - Controls
SECTION 11 - CONTROLS Lennox Mini-Split Service Manual / Page 113...
Page 114: Section 11.1 - M0Stat60Q Wireless Controller
SECTION 11.1 - M0STAT60Q WIRELESS CONTROLLER Lennox Mini-Split Service Manual / Page 114...
Page 115 • Turns the LCD display backlight on the indoor unit SPEED” or “ON/OFF” buttons. on or off. NOTE - SLEEP mode is only available when the unit is in COOL, HEAT or AUTO mode. Lennox Mini-Split Service Manual / Page 115...
Page 116 After approximately 2 seconds, the signal “H” will disappear and the set temperature will re-appear on the LCD display window. Lennox Mini-Split Service Manual / Page 116...
Page 117: Section 11.2 - M0Stat61Q-1 Wired Controller
SECTION 11.2 - M0STAT61Q-1 WIRED CONTROLLER Lennox Mini-Split Service Manual / Page 117...
Page 118 RESET LOCK ECONOMY RESET FAN SPEED SELECTION LOCK MODE Button • Select system operation modes. Push button to cycle through each setting. AUTO COOL HEAT POWER Button • Turns system on and off. Lennox Mini-Split Service Manual / Page 118...
Page 119: Section 12 - Start Up
SECTION 12 - START UP Lennox Mini-Split Service Manual / Page 119...
Page 120: Section 12.1 - General Start Up Information
SECTION 12.1 - GENERAL START UP INFORMATION Lennox Mini-Split Service Manual / Page 120...
Page 121: Outdoor Unit Spot Check Function
The capacity unit is horse power. If the indoor unit is not connected, the digital display tube will show: “――” C indoor unit capacity (9K:1HP,12K:1.2HP,18K:1.5HP) D indoor unit capacity E indoor unit capacity Lennox Mini-Split Service Manual / Page 121...
Page 122 D indoor unit evaporator temp. show “70”. If the indoor unit is not connected, the digital display tube (T2D) will show: “――” E indoor unit evaporator temp. (T2E) Condenser pipe temp.(T3) Outdoor ambient temp.(T4) Lennox Mini-Split Service Manual / Page 122...
Page 123 The last error or protection 00 means no malfunction and protection code F indoor unit capacity F Indoor unit capacity demand code F indoor unit evaporator outlet temp.(T2BF) F indoor unit room temp.(T1F) Lennox Mini-Split Service Manual / Page 123...
Page 124 Display Remark F indoor unit evaporator temp. (T2F) EXV open angle for F indoor unit Lennox Mini-Split Service Manual / Page 124...
Page 125: Outdoor Unit's Digital Display Tube
When PFC module protection occurs three times within 15 minutes, the LED displays “E6” or alternative displays between running frequency and “E6”(each displays 0.5s) In protection or malfunction, the LED displays error code or protection code. Lennox Mini-Split Service Manual / Page 125...
Page 126: Section 13 - Fault Codes
SECTION 13 - FAULT CODES Lennox Mini-Split Service Manual / Page 126...
Page 127 All other indoor units have digital displays on either the unit front cover or inside the control box or flash code displays on the main control board. Section 13.5 contains troubleshooting information for all Multi-Zone outdoor units • Multi-Zone outdoor units display a digital readout on the main control board. Lennox Mini-Split Service Manual / Page 127...
Page 128: Section 13.1 - Quick Reference Guide - Fault Codes
SECTION 13.1 - QUICK REFERENCE GUIDE - FAULT CODES Lennox Mini-Split Service Manual / Page 128...
Page 129: Single Zone 009/012 115Vac/208-230Vac Outdoor Units Quick Reference
Single Zone 009/012 115VAC/208-230VAC Outdoor Units Quick Reference Error Description Outdoor Unit Sticker Shown - See Indoor Unit for Error Code Lennox Mini-Split Service Manual / Page 129...
Page 130: Single Zone 018/030 208-230Vac Outdoor Units Quick Reference
Control board chip communication error Fast flash Fast flash Fast flash NOTE Slow flash----Flashing at 1Hz Fast flash----Flashing at 2Hz IDU--Indoor unit ODU---Outdoor unit Outdoor Unit Sticker Shown - See Indoor Unit for Error Code Lennox Mini-Split Service Manual / Page 130...
Page 131: Multi-Zone Outdoor Units Quick Reference
Outdoor Compressor current overload sensed High temperature sensed at compressor discharge line High temperature sensed at outdoor coil Inverter module (IPM) error Outdoor Unit Sticker Shown - See Indoor Unit for Additional Error Code Information Lennox Mini-Split Service Manual / Page 131...
Page 132: Indoor Unit Fault Code Units Quick Reference For All Indoor Units
Mode conflict Compressor high-pressure or low-pressure switch open Indoor Unit Sticker Shown - ALL Indoor Units 09/24 Display NOTE flash , light, X extinguished Indoor Unit Sticker Shown - ALL Indoor Units 09/30-48 Lennox Mini-Split Service Manual / Page 132...
Page 133: Section 13.2 - Troubleshooting Single Zone Outdoor Units
SECTION 13.2 - TROUBLESHOOTING SINGLE ZONE OUTDOOR UNITS Lennox Mini-Split Service Manual / Page 133...
Page 134 PWM synchronization failure Fast flash IGBT over-current/IPM over-current Fast flash Control board chip communication error Fast flash Fast flash Fast flash NOTE Slow flash----Flashing at 1Hz Fast flash----Flashing at 2Hz IDU--Indoor unit ODU---Outdoor unit Lennox Mini-Split Service Manual / Page 134...
Page 135 Fault Code LED Illustrative Drawing of Board Shown - Actual Unit May Differ MPA009S4S-1L and MPA012S4S-1L Lennox Mini-Split Service Manual / Page 135...
Page 136 KFR 26W $BP2- 180( D YD C - 390- N 3) . D . 13. W P2. 1 Power ON Fault Code LEDs Illustrative Drawing of Board Shown - Actual Unit May Differ MPA009S4S-1P and MPA012S4S-1P Lennox Mini-Split Service Manual / Page 136...
Page 137 C E- KFR 72W / BP3( 2) - 350( 311+0515+1246+STK5C 4U 341/ 340) . D . 13. W P2. 1 Fault Code LEDs Illustrative Drawing of Board Shown - Actual Unit May Differ MPA018S4S-1P Lennox Mini-Split Service Manual / Page 137...
Page 138 CompTop LOW/HIGH IC16 CN25 IC12 CONdebug1 IC13 L-OUT 4-WAY FUSE1 HEAT1 T5A 250VAC L-IN HEAT2 PTC1 CN29 202302130895 N-OUT CE-KFR80W/BP3T4N1(DC MOTOR)-310.D.03.WP1-1 N-IN Illustrative Drawing of Board Shown - Actual Unit May Differ MPA024S4S-1P Lennox Mini-Split Service Manual / Page 138...
Page 139 C 60 C 11 202302141206 EU - KFR 105W / BP3T5N 1- 350S. D . 13. W P1- 1 Fault Code LEDs Illustrative Drawing of Board Shown - Actual Unit May Differ MPA030S4S-1P Lennox Mini-Split Service Manual / Page 139...
Page 140: Section 13.3 - Troubleshooting Multi-Zone Outdoor Units
SECTION 13.3 - TROUBLESHOOTING MULTI- ZONE OUTDOOR UNITS Lennox Mini-Split Service Manual / Page 140...
Page 141 Indoor unit #6 coil outlet temp. sensor error High pressure switch open Low pressure switch open Outdoor Compressor current overload sensed High temperature sensed at compressor discharge line High temperature sensed at outdoor coil Inverter module (IPM) error Lennox Mini-Split Service Manual / Page 141...
Page 142 MPA030S4M-1P Shown - Actual Unit May Differ Lennox Mini-Split Service Manual / Page 142...
Page 143: E0 Fault Code
PCB main chip does not receive feedback from EEPROM chip. EEPROM: a read-only memory whose contents can be erased and reprogrammed using a pulsed voltage. For the location of EEPROM chip, please refer to the below photos. Lennox Mini-Split Service Manual / Page 143...
Page 144: E0 Flow Chart
E0 Flow Chart Outdoor EEPROM malfunction Power off, then restart the unit 3 minutes later. Does the problem still exist? Replace the outdoor main PCB. Outdoor PCB(M3OC-30HRFN1-M) Lennox Mini-Split Service Manual / Page 144...
Page 145: E2 Fault Code
Communication malfunction between outdoor unit and all indoor units. General Note: Indoor unit does not receive the communication from outdoor unit for 120 seconds or outdoor unit does not receive the communication from any one indoor unit for 180 seconds. Lennox Mini-Split Service Manual / Page 145...
Page 146: E2 Flowchart
(2 for 2-zone, 3 for Problem Solved 3-zone, 4 for 4-zone). Refer PIC 4. No ﬁ rst time No second time Change outdoor unit PCB as- sembly totally (include wiring). Lennox Mini-Split Service Manual / Page 146...
Page 147 When AC is normal running, the voltage will move alternately between positive value and negative value. Pic 2: IPM (for 2-zone/3-zone) Power (some Power (some models) modles) Self-Check OK Opera ng Pic 2 Lennox Mini-Split Service Manual / Page 147...
Page 148 Pic 3: Main board LED when power on and unit standby. Pic 4: Check point button, press 1 time to check how many indoor units are connected. Lennox Mini-Split Service Manual / Page 148...
Page 149: E3 Fault Code
E3 Fault Code Basic Description: Communication error between outdoor unit main control and IPM. General Note: PCB main chip does not receive feedback from IPM during 60 seconds. Lennox Mini-Split Service Manual / Page 149...
Page 150: E3 Flow Chart
Replace IPM board, and then check whether the system can run normally. Replace outdoor main board, and then check whether the system can run nor- mally. Problem Solved. Replace the electric control box. Lennox Mini-Split Service Manual / Page 150...
Page 151 The normal value should be around 5V. Use a multimeter to test the DC voltage between black pin and red pin of signal wire. The normal value should be around 12V.. Lennox Mini-Split Service Manual / Page 151...
Page 152: E4 Fault Code
Basic Description: Temp. sensor error (outdoor coil sensor, outdoor ambient sensor, compressor discharge sensor, indoor unit coil outlet temp. sensor) General Note: Error displays if voltage is lower than 0.06V or higher than 4.94V. Lennox Mini-Split Service Manual / Page 152...
Page 153: E4 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 153...
Page 154: E5 Fault Code
E5 Fault Code Basic Description: High or low voltage protection General Note: An abnormal voltage rise or drop is detected by checking the speciﬁ ed voltage detection circuit. Lennox Mini-Split Service Manual / Page 154...
Page 155: E5 Flow Chart
18-27KBtu/h; DC277-410V for 36KBtu/h. Replace bridge rectiﬁ ers, and then check whether the system can run normally(Only for 4-zone) Replace IPM board, and then check for normal unit operation Replace outdoor main board. Problem Solved. Lennox Mini-Split Service Manual / Page 155...
Page 156 IPM (for 2-zone and 3-zone) IPM (for 4-zone) P-N (for 2-zone and 3-zone) Lennox Mini-Split Service Manual / Page 156...
Page 157 P-N (for 4-zone) Lennox Mini-Split Service Manual / Page 157...
Page 158 Bridge rectifier for 2-zone and 3-zone Bridge rectifier for 4-zone Lennox Mini-Split Service Manual / Page 158...
Page 159 Remark: Measure the DC voltage between + and - port. The normal value should be 190V~250V. Lennox Mini-Split Service Manual / Page 159...
Page 160: E6 Fault Code
PFC module protection. (For MPA036S4M-1P and MPA048S4M-1P) General Note: When the voltage signal that PFC sends to main control board is abnormal, the display LED will show “E6” and AC will turn off. Lennox Mini-Split Service Manual / Page 160...
Page 161: E6 Flow Chart
Check if the inductance of the PFC module is good. If the inductor is Replace the inductor. good, the resistance value of the two ports is 0. Replace the PFC module. Problem Solved. Lennox Mini-Split Service Manual / Page 161...
Page 162 Inductor Two terminals of the inductor Lennox Mini-Split Service Manual / Page 162...
Page 163 Lennox Mini-Split Service Manual / Page 163...
Page 164: E8 Fault Code
Outdoor DC fan motor speed error. General Note: When outdoor fan speed keeps too low (300RPM) or too high(2400RPM) for certain time, the unit will stop and the LED will display the failure. Lennox Mini-Split Service Manual / Page 164...
Page 165: E8 Flow Chart
Wheel and shaft should spin evenly and balanced. Check all wiring connections. Correct faulty corrections. Check main PCB, see index 1. Replace the main PCB. Replace the fan motor. Lennox Mini-Split Service Manual / Page 165...
Page 166 If the value of the voltage is not in the range shown in below table, the PCB faulty and should be replaced. DC motor voltage input and output Color Signal Voltage Vs/Vm 200~380V Black White 13.5~16.5V Yellow 0~6.5V Blue 13.5~16.5V Lennox Mini-Split Service Manual / Page 166...
Page 167 Lennox Mini-Split Service Manual / Page 167...
Page 168: F1 Fault Code
F1 Fault Code Basic Description: Indoor unit #1 coil outlet temp. sensor error General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 168...
Page 169: F1 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 169...
Page 170: F2 Fault Code
F2 Fault Code Basic Description: Indoor unit #2 coil outlet temp. sensor error General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 170...
Page 171: F2 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 171...
Page 172: F3 Fault Code
F3 Fault Code Basic Description: Indoor unit #3 coil outlet temp. sensor error General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 172...
Page 173: F3 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 173...
Page 174: F4 Fault Code
F4 Fault Code Basic Description: Indoor unit #4 coil outlet temp. sensor error General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 174...
Page 175: F4 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 175...
Page 176: F5 Fault Code
F5 Fault Code Basic Description: Indoor unit #5 coil outlet temp. sensor error General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 176...
Page 177: F5 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 177...
Page 178: F6 Fault Code
F6 Fault Code Basic Description: Not applicable Lennox Mini-Split Service Manual / Page 178...
Page 179: P1 Fault Code
P1 Fault Code Basic Description: High pressure switch open. General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 179...
Page 180: P1 Flow Chart
Check if the outdoor fan runs properly outdoor fan motor. Check outdoor coils. The outdoor unit coils should be Clean outdoor coils. clean and free of any debris. Replace outdoor main board. Check whether the refrigerant system is OK. Lennox Mini-Split Service Manual / Page 180...
Page 181 Lennox Mini-Split Service Manual / Page 181...
Page 182: P2 Fault Code
P2 Fault Code Basic Description: Low pressure switch open General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 182...
Page 183: P2 Flow Chart
Fully open the high pressure valve. Refer to the solution of fan speed mal- function (E8). Find out the cause correct Check if the indoor fan runs properly in cooling mode. Replace outdoor main board. Lennox Mini-Split Service Manual / Page 183...
Page 184 Lennox Mini-Split Service Manual / Page 184...
Page 185: P3 Fault Code
P3 Fault Code Basic Description: Outdoor compressor current overload sensed General Note: If the outdoor current exceeds the current limit value, the LED will display the failure. Lennox Mini-Split Service Manual / Page 185...
Page 186: P3 Flow Chart
Perform proper vacuum procedures, then Judge 5: The refrigerant pipe is blocked. restart system. Replace outdoor main board, and check whether the system can run normally. Replace the electric control box. Problem Solved. Lennox Mini-Split Service Manual / Page 186...
Page 187 Lennox Mini-Split Service Manual / Page 187...
Page 188: P4 Fault Code
High temperature sensed at compressor discharge line. General Note: When the compressor discharge temperature(T5) is more than 115°C for 10 seconds, the compressor will stop and restart till T5 is less than 90°C. Lennox Mini-Split Service Manual / Page 188...
Page 189: P4 Flow Chart
Measure the resistance value of compressor dis- Replace the compressor charge temp. sensor. If the value is not normal is discharge temp. sensor. normal refer to the Appendix 2? Replace outdoor main PCB. Replace high pressure valve assy. Lennox Mini-Split Service Manual / Page 189...
Page 190: P5 Fault Code
Basic Description: High temperature sensed at outdoor coil. General Note: When outdoor pipe temperature is more than 65°C, the unit will stop, and unit runs again when outdoor pipe temperature is less than 52°C. Lennox Mini-Split Service Manual / Page 190...
Page 191: P5 Flow Chart
Conﬁ rm if system has the correct refrigerant charge. Remove remaining refrigerant charge, pressure test and locate Replace the outdoor main board. leak. Add correct charge. Test system. If system fails to operate correctly replace outdoor board. Lennox Mini-Split Service Manual / Page 191...
Page 192: P6 Fault Code
Basic Description: Inverter module (IPM) error. General Note: When the voltage signal that IPM sends to the compressor drive chip is abnormal, the display LED will show “P6” and AC will turn off. Lennox Mini-Split Service Manual / Page 192...
Page 193: P6 Flowchart
(for M4OC- 36HRFN1-M& M4OC- 36HRDN1-M) Replace the wir- ing or reactor or Replace the compressor, replace the PFC check whether the system module(for M4OC- operates normally? 36HRFN1-M) Problem Solved Lennox Mini-Split Service Manual / Page 193...
Page 194: Section 13.4 - Indoor Unit Fault Codes
SECTION 13.4 - INDOOR UNIT FAULT CODES Lennox Mini-Split Service Manual / Page 194...
Page 195 Mode conflict Compressor high-pressure or low-pressure switch open Indoor Unit Sticker Shown - ALL Indoor Units 09/24 Display NOTE flash , light, X extinguished Indoor Unit Sticker Shown - ALL Indoor Units 09/30-48 Lennox Mini-Split Service Manual / Page 195...
Page 196 OPERATION indication lamp: This lamp illuminates when the air conditioner is in operation. TIMER indication lamp: Lights up during Timer operation. Temperature indicator: Displays the temperature settings when the air conditioner is operational. Displays the malfunction code. Wall-Mounted Unit Lennox Mini-Split Service Manual / Page 196...
Page 197: E0 Fault Code
E0 Fault Code Basic Description: Indoor unit EEPROM error General Note: PCB main chip does not receive communication from EEPROM chip. Lennox Mini-Split Service Manual / Page 197...
Page 198: E0 Flowchart
Is it still displaying the error code? If the EEPROM chip is soldered on PCB, re- Insert the EEPROM properly place the PCB. Otherwise, check whether the EEPROM chip is plugged in PCB properly? Replace the indoor PCB. Lennox Mini-Split Service Manual / Page 198...
Page 199: E1 Fault Code
E1 Fault Code Basic Description: Communication malfunction between indoor unit and outdoor unit. General Note: PCB main chip does not receive feedback from IPM module during 60 seconds. Lennox Mini-Split Service Manual / Page 199...
Page 200: E1 Flow Chart
Replace IPM board, and then check whether the system can run normally. Replace outdoor main board, and then check whether the system can run nor- mally. Problem Solved. Replace the electric control box. Lennox Mini-Split Service Manual / Page 200...
Page 201 The normal value should be around 5V. Use a multimeter to test the DC voltage between black pin and red pin of signal wire. The normal value should be around 12V.. Lennox Mini-Split Service Manual / Page 201...
Page 202: E3 Fault Code
E3 Fault Code Basic Description: Indoor fan speed error. General Note: When indoor fan speed runs too low (300RPM) for a certain time, the unit will stop and the LED will display the error. Lennox Mini-Split Service Manual / Page 202...
Page 203: E3 Flow Chart
Correct the connections. connected correctly? Measure the voltage for the fan motor from the main PCB. Is the voltage cor- rect? Replace the electric control box. Replace the main PCB Replace the fan motor Lennox Mini-Split Service Manual / Page 203...
Page 204: E4 Fault Code
E4 Fault Code Basic Description: Indoor return air temperature sensor error. General Note: If the voltage is lower than 0.06V or higher than 4.94V, the LED will display the error. Lennox Mini-Split Service Manual / Page 204...
Page 205: E4 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 205...
Page 206: E5 Fault Code
E5 Fault Code Basic Description: Indoor Coil Temperature Sensor Error General Note: If the voltage is lower than 0.06V or higher than 4.94V, the LED will display the error. Lennox Mini-Split Service Manual / Page 206...
Page 207: E5 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 207...
Page 208: Ec Fault Code
If the temperature of T2 drops per this formula three times in the ﬁ rst 5 minutes of operation, the system shuts down and the error code displays. For this formula “Tcool” = the T2 temperature at startup. T2 < Tcool - 3.6°F (2°C) Lennox Mini-Split Service Manual / Page 208...
Page 209: Ec Flow Chart
Check to see if cool air is blowing out of it functioning the indoor air outlet Replace the indoor PCB Check for refrigerant leaks. Repair leaks and re- charge system. Check for restriction in refrigerant lines. Clear restriction. Lennox Mini-Split Service Manual / Page 209...
Page 210: Ee Fault Code
EE Fault Code Basic Description: Water-level alarm malfunction. (For cassette/A5 duct) General Note: If the sampling voltage is not 5V, the LED will display the failure. Lennox Mini-Split Service Manual / Page 210...
Page 211: Ee Flow Chart
If the water-level switch is inserted well? switch well. Replace the water-level If the water-level switch is broken? switch. Replace the water pump, If malfunction is still not solved. Replace the indoor main PCB. Lennox Mini-Split Service Manual / Page 211...
Page 212: F0 Fault Code
F0 Fault Code Basic Description: Outdoor compressor current overload sensed General Note: If the outdoor current exceeds the current limit value, the LED will display the failure. Lennox Mini-Split Service Manual / Page 212...
Page 213: F0 Flow Chart
Perform proper vacuum procedures, then Judge 5: The refrigerant pipe is blocked. restart system. Replace outdoor main board, and check whether the system can run normally. Replace the electric control box. Problem Solved. Lennox Mini-Split Service Manual / Page 213...
Page 214: F1 Fault Code
F1 Fault Code Basic Description: Outdoor Temperature Sensor T4 Error. General Note: If the voltage is lower than 0.06V or higher than 4.94V, the LED will display the error. Lennox Mini-Split Service Manual / Page 214...
Page 215: F1 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 215...
Page 216: F2 Fault Code
F2 Fault Code Basic Description: Faulty Outdoor Coil Temperature Sensor T3/T5. General Note: If the voltage is lower than 0.06V or higher than 4.94V, the LED will display the error. Lennox Mini-Split Service Manual / Page 216...
Page 217: F2 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 217...
Page 218: F3 Fault Code
Basic Description: Compressor discharge temperature sensor error General Note: When the compressor discharge temperature(T5) is more than 115°C for 10 seconds, the compressor will stop and restart till T5 is less than 90°C. Lennox Mini-Split Service Manual / Page 218...
Page 219: F3 Flow Chart
Measure the resistance value of compressor dis- Replace the compressor charge temp. sensor. If the value is not normal is discharge temp. sensor. normal refer to the Appendix 2? Replace outdoor main PCB. Replace high pressure valve assy. Lennox Mini-Split Service Manual / Page 219...
Page 220: F4 Fault Code
PCB main chip does not receive feedback from EEPROM chip. EEPROM: a read-only memory whose contents can be erased and reprogrammed using a pulsed voltage. For the location of EEPROM chip, please refer to the below photos. Lennox Mini-Split Service Manual / Page 220...
Page 221: F4 Flow Chart
F4 Flow Chart Outdoor EEPROM malfunction Power off, then restart the unit 3 minutes later. Does the problem still exist? Replace the outdoor main PCB. Outdoor PCB(M3OC-30HRFN1-M) Lennox Mini-Split Service Manual / Page 221...
Page 222: F5 Fault Code
Basic Description: Outdoor unit fan speed error General Note: When outdoor fan speed keeps too low (300RPM) or too high(2400RPM) for certain time, the unit will stop and the LED will display the failure. Lennox Mini-Split Service Manual / Page 222...
Page 223: F5 Flow Chart
Wheel and shaft should spin evenly and balanced. Check all wiring connections. Correct faulty corrections. Check main PCB, see index 1. Replace the main PCB. Replace the fan motor. Lennox Mini-Split Service Manual / Page 223...
Page 224: F6 Fault Code
F6 Fault Code Basic Description: Indoor Unit Evaporator Outlet Coil Temperature Sensor Faulty General Note: If the voltage is lower than 0.06V or higher than 4.94V, the LED will display the error. Lennox Mini-Split Service Manual / Page 224...
Page 225: F6 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- door PCB. Is it normal? Replace the sensor. Lennox Mini-Split Service Manual / Page 225...
Page 226: P0 Fault Code
IPM module or IGBT overcurrent protection. General Note: When the voltage signal that IPM sends to the compressor drive chip is abnormal, the display LED will show “P6” and AC will turn off. Lennox Mini-Split Service Manual / Page 226...
Page 227: P0 Flowchart
(for M4OC- 36HRFN1-M& M4OC- 36HRDN1-M) Replace the wir- ing or reactor or Replace the compressor, replace the PFC check whether the system module(for M4OC- operates normally? 36HRFN1-M) Problem Solved Lennox Mini-Split Service Manual / Page 227...
Page 228: P1 Fault Code
P1 Fault Code Basic Description: High or Low voltage protection General Note: An abnormal voltage rise or drop is detected by checking the speciﬁ ed voltage detection circuit. Lennox Mini-Split Service Manual / Page 228...
Page 229: P1 Flow Chart
18-27KBtu/h; DC277-410V for 36KBtu/h. Replace bridge rectiﬁ ers, and then check whether the system can run normally(Only for 4-zone) Replace IPM board, and then check for normal unit operation Replace outdoor main board. Problem Solved. Lennox Mini-Split Service Manual / Page 229...
Page 230: P3 Fault Code
The outdoor unit will resume operation when either: The OUTDOOR temperature is higher than -7.6°F (-22°C) for 10 minutes and compressor has been stopped for 1 hour Outdoor temperature is higher than 23°F (-5°C) for 10 minutes Lennox Mini-Split Service Manual / Page 230...
Page 231: P3 Flow Chart
P3 Flow Chart Lennox Mini-Split Service Manual / Page 231...
Page 232: P4 Fault Code
P4 Fault Code Basic Description: Compressor drive error General Note: An abnormal inverter compressor drive is detected by a special detection circuit, including communication signal detection, voltage detection, compressor rotation speed signal detection and etc Lennox Mini-Split Service Manual / Page 232...
Page 233: P4 Flow Chart
PCB. Refer to the fault code fan speed malfunc- Check the outdoor fan and the outdoor unit ventilation. tion (E8). Check the compressor resistance values. Replace the compressor. Replace the outdoor main PCB. Lennox Mini-Split Service Manual / Page 233...
Page 234: P5 / -- Fault Code
B will change to stand by and A will be no change. Cooling mode Heating mode Cooling Mode Heating Mode No = No mode conﬂ ict. Yes = Mode conﬂ ict Lennox Mini-Split Service Manual / Page 234...
Page 235: P6 Fault Code
Compressor high-pressure or low-pressure switch open General Note: If the sampling voltage of pressure switch is not 5V, the LED will display the failure. Test each pressure switch separately following these ﬂ ow charts. Lennox Mini-Split Service Manual / Page 235...
Page 236: P6 Flow Charts
Check if the outdoor fan runs properly outdoor fan motor. Check outdoor coils. The outdoor unit coils should be Clean outdoor coils. clean and free of any debris. Replace outdoor main board. Check whether the refrigerant system is OK. Lennox Mini-Split Service Manual / Page 236...
Page 237 Fully open the high pressure valve. Refer to the solution of fan speed mal- function (E8). Find out the cause correct Check if the indoor fan runs properly in cooling mode. Replace outdoor main board. Lennox Mini-Split Service Manual / Page 237...
Page 238 Lennox Mini-Split Service Manual / Page 238...
Page 239: P7 Fault Code
P7 Fault Code Basic Description: Outdoor IGBT temperature sensor error General Note: If the voltage is lower than 0.06V or higher than 4.94V, the LED will display the error. Lennox Mini-Split Service Manual / Page 239...
Page 240: P7 Flow Chart
PCB. Are the connec- tions good? Check the resistance value of the sensor via Appendix 1 and Appendix 2. Replace indoor or out- Is it normal? door PCB. Replace the sensor. Lennox Mini-Split Service Manual / Page 240...
Page 241: Temperature Sensor Resistance Value Table (°C--K)
0.27078 18.7177 3.19183 0.80132 0.26408 17.8005 3.07075 0.77709 0.25757 16.9341 2.95896 0.75373 0.25125 16.1156 2.84421 0.73119 0.24512 15.3418 2.73823 0.70944 0.23916 14.6181 2.63682 0.68844 0.23338 13.9180 2.53973 0.66818 0.22776 13.2631 2.44677 0.64862 0.22231 Lennox Mini-Split Service Manual / Page 241...
Page 242: Discharge Temperature Sensor Table (°C--K)
5.157 1.674 109.8 19.69 1.632 104.6 18.96 4.849 99.69 18.26 4.703 95.05 17.58 4.562 90.66 16.94 4.426 86.49 16.32 4.294 B(25/50)=3950K 82.54 15.73 4.167 78.79 15.16 4.045 R(90°C)=5KΩ±3% 75.24 14.62 3.927 71.86 3.812 Lennox Mini-Split Service Manual / Page 242...
Page 243: Celsius To Fahrenheit Conversion Table
48 50 52 54 56 58 60 62 64 66 68 70 72 °C 23 24 25 26 27 28 29 30 31 32 33 34 35 °F 74 76 78 80 82 84 86 88 90 92 94 96 98 Lennox Mini-Split Service Manual / Page 243...
Page 244: Compressor Check
Measure the resistance value of each winding by using the tester. This can also be used to check for shorted compressor windings, and identifying terminals when they are no longer legible. Position Resistance Value DA150S1C-20FZ DA250S2C-30MT TNB306FPGMC-L MNB36FAAMC-L Blue - Red 0.95Ω (20°C/68°F) 0.55Ω (20°C/68°F) 0.53Ω (20°C/68°F) 0.44Ω (20°C/68°F) Lennox Mini-Split Service Manual / Page 244...
Page 245: Ipm Check
Use a digital tester to measure the resistance between P and UVWN; UVW and N. Normal Normal Resistance Digital Tester Digital Tester Resistance Value Value (+)Red (-)Black (+)Red (-)Black ∞ ∞ (Several MΩ) (Several MΩ) (+)Red Lennox Mini-Split Service Manual / Page 245...
Page 246: Ac Fan Motor
Red - 76Ω±8% 19Ω±8% 252Ω±8% 88Ω±8% 150Ω±8% 374.3Ω±8% 138Ω±8% Yellow (20°C) (20°C) (20°C) (20°C) (20°C) (20°C) (20°C) Yellow - 76Ω±8% 19Ω±8% 252Ω±8% 88Ω±8% 150Ω±8% 374.3Ω±8% 138Ω±8% Blue (20°C) (20°C) (20°C) (20°C) (20°C) (20°C) (20°C) Lennox Mini-Split Service Manual / Page 246...
Page 247: 4-Way Valve
If the value of the voltage is not in the range, the PCB must have problems and need to be replaced. 2 Turn off the power, use a digital tester to measure the resistance. The value should be 1.8~2.5 KΩ. Lennox Mini-Split Service Manual / Page 247...
Page 248: Exv Check
EXV Check Disconnect the connectors. Resistance to EXV Coil Color of lead wire Normal Value Red- Blue Red - Yellow About 50Ω Brown-Orange Brown-White Lennox Mini-Split Service Manual / Page 248...
Page 249 Red- Blue Red - Yellow Lennox Mini-Split Service Manual / Page 249...
Page 250 Brown-Orange Brown-White Lennox Mini-Split Service Manual / Page 250...
Page 251: Low Voltage Protection
NOTE - If the low voltage protection occurs and not resumes within 3 minutes, it will keep the protection always after restart the machine. VOLTAGE No limit VOLT_RST1_ADD VOLT_LTM1_ADD VOLT_LTM_FREQ1_ADD VOLT_RST2_ADD VOLT_LTM2_ADD VOLT_LTM_FREQ2_ADD Lennox Mini-Split Service Manual / Page 251...
Page 252: Electronic Functions Abbreviations
If 215.6°F (102°C) < T5 < 244.4°F (115°C), decrease the frequency to the lower level every two minutes until to F1. If T5 < 244.4°F (115°C) for ten seconds, the compressor will stop and restart till T5 < 194°F (90°C) Lennox Mini-Split Service Manual / Page 252...
Page 253: Compressor Preheating Functions
When T4< 37.4°F (3°C) and the compressor is not running for 3 hours, the crankcase heater will be active. Preheating Release If T4>41°F (5°C) or the indoor has capacity demand, the crankcase heater will stop Condition work. Lennox Mini-Split Service Manual / Page 253...
Page 254: Capacity Request Calculation
17°C - 25°C <17°C Cooling >77°F 62.6°F - 77°F <62.6°F Modify Rate 100% NOTE - The ﬁ nal result is integer. In low ambient cooling mode, modify rate is ﬁ xed as 40%. Lennox Mini-Split Service Manual / Page 254...
Page 255 NOTE - Average value of T2: Sum T2 value of all indoor units)/ (indoor units number). According to the ﬁ nal capacity request to conﬁ rm the operating frequency, as following table. Heating capacity improved in low ambient heating Lennox Mini-Split Service Manual / Page 255...
Page 256: Defrost Control
Defrost mode ends when any of the following conditions are met. 1. T3 > 64.4°F (18°C) 2. T3 remains > 43.4 °F (8°C) for 80 seconds 3. System has been in defrost mode for 10 minutes Lennox Mini-Split Service Manual / Page 256...
Page 257: Outdoor Fan Control
T3. When T3≥38°C (100.4°F) or when T4≥20°C (68°F), the outdoor fan will choose the speed according to T4 again. Exit low ambient cooling mode run with high fan for 1 minute Lennox Mini-Split Service Manual / Page 257...
Page 258: Four-Way Valve Control
16p close; If average+2≥the T2≥ average-2, the relevant valve’s open range remains; If the T2<average-2, the relevant valve needs more 16p open. This modiﬁ cation will be carry out every 2 minutes. Lennox Mini-Split Service Manual / Page 258...

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