Lennox MODEL L - M4 UNIT CONTROLLER Error Codes
Unit controller
Model numbers in this family: M4 Unit Controller, MODEL L - M4 UNIT CONTROLLER
- 1 ERRATIC POWER (single phase units)
- 100 - 102 RESERVED
- 103 ADVANCED CONTROL SETUP ERROR
- 104 - 105 RESERVED
- 106 BUILDING PRESSURE SENSOR PROBLEM
- 107 DUCT SUPPLY PRESS SENSOR PROBLEM
- 108 SUPPLY DUCT PRESS LIMIT EXCEEDED
- 109 STRIKE 3 SUPPLY DUCT PRESSURE LIMIT
- 110 WAITING ON SENSOR DATA
- 111 PROFILE ERROR
- 112 - 120 RESERVED
- 12 HIGH PRESSURE SWITCH COMPRESSOR 1
- 121 LINE FREQUENCY MISMATCH
- 122 24VAC PRIMARY VOLTAGE LOW
- 123 24VAC PRIMARY VOLTAGE HIGH
- 124 24VAC SECONDARY VOLTAGE LOW
- 125 24VAC SECONDARY VOLTAGE HIGH
- 126 LINE PHASING MISMATCH
- 127 RESERVED
- 128 RESERVED
- 129 VFD SHUTDOWN
- 13 HIGH PRESSURE STRIKE 3 COMPRESSOR 1
- 130 VFD BYPASS ENGAGED
- 131 RESERVED
- 132 VFD BYPASS UNCONFIGURED
- 133 - 136 RESERVED
- 137 DAMPER STUCK CLOSED
- 138 RESERVED
- 139 DAMPER STUCK OPEN
- 14 HIGH PRESSURE SWITCH COMPRESSOR 2
- 140 - 146 RESERVED
- 147 DAMPER FEEDBACK LOSS
- 148 RESERVED
- 149 OA DIFF PRESS SENSOR ERROR
- 15 HIGH PRESSURE STRIKE 3 - COMPRESSOR 2
- 150 NOT ECONOMIZING WHEN OAS
- 151 ECONOMIZING WHEN OANS
- 152 - 164 RESERVED
- 16 HIGH PRESSURE SWITCH - COMPRESSOR 3
- 165 ECONOMIZER UNCONFIGURED
- 166 GAS CAB NO OPEN PROOF GV1
- 167 GAS CAB NO OPEN PROOF GV2
- 168 - 169 RESERVED
- 17 HIGH PRESSURE STRIKE 3 - COMPRESSOR 3
- 170 POWER EXHAUST UNCONFIGURED
- 171 POWER EXHAUST CONFIGURATION ERROR
- 172 RESERVED
- 173 AIRFLOW SWITCH CONFIGURATION ERROR
- 174 BYPASS DAMPER CONFIGURATION ERROR
- 175 RESERVED
- 176 SBUS OBSOLETE M2 COMMAND
- 177 NO MODEL NUMBER
- 178 - 185 RESERVED
- 18 HIGH PRESSURE SWITCH - COMPRESSOR 4
- 186 BLOWER MOTOR FAULT
- 187 INVERTER MINOR
- 188 INVERTER MAJOR
- 189 INVERTER FATAL
- 19 HIGH PRESSURE STRIKE 3 - COMPRESSOR 4
- 190 INVERTER COMMUNICATION ERROR
- 191 INVERTER VOLTAGE MISMATCH
- 192 HIGH TEMPERATURE (S7) COMPRESSOR 1
- 193 HIGH TEMPERATURE (S7) STRIKE 3 COMPRESSOR 1
- 194 CRITICAL LOSS CONDENSER AIRFLOW
- 195 CRITICAL LOSS OF CHARGE COMPRESSOR 1
- 196 CRITICAL LOSS OF CHARGE COMPRESSOR 2
- 197 CRITICAL LOSS OF CHARGE COMPRESSOR 3
- 198 CRITICAL LOSS OF CHARGE COMPRESSOR 4
- 199 CRITICAL LOSS OF EVAPORATOR AIRFLOW
- 2 - 3 RESERVED
- 20 PHASE MONITOR FAULT
- 200 COMPRESSOR 1 NOT OPERATING
- 201 COMPRESSOR 2 NOT OPERATING
- 202 COMPRESSOR 3 NOT OPERATING
- 203 COMPRESSOR 4 NOT OPERATING
- 204 COMPRESSOR 1 TXV FAILED CLOSED
- 205 COMPRESSOR 2 TXV FAILED CLOSED
- 206 COMPRESSOR 3 TXV FAILED CLOSED
- 207 COMPRESSOR 4 TXV FAILED CLOSED
- 208 - 217 RESERVED
- 21 RESERVED
- 218 SLT SENSOR FAILURE COMPRESSOR 1
- 219 SLT SENSOR FAILURE COMPRESSOR 2
- 22 LOW PRESSURE SWITCH COMPRESSOR 1
- 220 SLT SENSOR FAILURE COMPRESSOR 3
- 221 SLT SENSOR FAILURE COMPRESSOR 4
- 222 LT SENSOR FAILURE COMPRESSOR 1
- 223 LT SENSOR FAILURE COMPRESSOR 2
- 224 LT SENSOR FAILURE COMPRESSOR 3
- 225 LT SENSOR FAILURE COMPRESSOR 4
- 226 SST SENSOR FAILURE COMPRESSOR 1
- 227 SST SENSOR FAILURE COMPRESSOR 2
- 228 SST SENSOR FAILURE COMPRESSOR 3
- 229 SST SENSOR FAILURE COMPRESSOR 4
- 23 STRIKE 3 LOW PRESSURE COMPRESSOR 1
- 230 ST SENSOR FAILURE COMPRESSOR 1
- 231 ST SENSOR FAILURE COMPRESSOR 2
- 232 ST SENSOR FAILURE COMPRESSOR 3
- 233 ST SENSOR FAILURE COMPRESSOR 4
- 234 DSI BOARD 1 ERROR
- 235 DSI BOARD 2 ERROR
- 236 DSI BOARD 1 FLAME LOSS
- 237 DSI BOARD 2 FLAME LOSS
- 238 DSI BOARD 1 MODBUS ERROR
- 239 DSI BOARD 2 MODBUS ERROR
- 24 LOW PRESSURE SWITCH COMPRESSOR 3
- 240 DSI BOARD 1 VALVE FAULT
- 241 DSI BOARD 2 VALVE FAULT
- 242 DSI BOARD 1 LOCKOUT
- 243 DSI BOARD 2 LOCKOUT
- 244 BLOWER DIFFERENTIAL PRESSURE SENSOR ERROR
- 245 - 512 RESERVED
- 25 STRIKE 3 LOW PRESSURE COMPRESSOR 2
- 26 LOW PRESSURE SWITCH COMPRESSOR 3
- 27 STRIKE 3 LOW PRESSURE COMPRESSOR 3
- 28 LOW PRESSURE SWITCH COMPRESSOR 4
- 29 STRIKE 3 LOW PRESSURE COMPRESSOR 4
- 30 DRAIN PAN OVERFLOW SWITCH
- 31 RESERVED
- 32 EVAPORATOR FROZEN COMPRESSOR 1
- 33 STRIKE 3 EVAPORATOR FROZEN COMPRESSOR 1
- 34 EVAPORATOR FROZEN COMPRESSOR 2
- 35 STRIKE 3 EVAPORATOR FROZEN COMPRESSOR 2
- 36 EVAPORATOR FROZEN COMPRESSOR 3
- 37 STRIKE 3 EVAPORATOR FROZEN COMPRESSOR 3
- 38 EVAPORATOR FROZEN COMPRESSOR 4
- 39 STRIKE 3 EVAPORATOR FROZEN COMPRESSOR 4
- 4 SMOKE DETECTED
- 40 RETURN AIR OVER HEAT LIMIT
- 41 RETURN AIR UNDER COOL LIMIT
- 42 - 43 RESERVED
- 44 GAS VALVE ON NO DEMAND GV1
- 45 GAS VALVE ON NO DEMAND GV2
- 46 - 49 RESERVED
- 5 BLOWER - NO AIRFLOW DETECTED
- 50 PRIMARY HEAT 1 LIMIT OPEN S10
- 51 STRIKE3 PRIMARY HEAT 1 LIMIT OPEN
- 513 ERROR READING USB DEVICE
- 514 USB DEVICE NOT MOUNTED
- 515 USB DEVICE FULL
- 516 INVALID DIN NUMBER
- 517 WCS LOW BATTERY CRITICAL
- 518 WCS LOW BATTERY HIGH
- 519 WCS LOW BATTER LOW
- 52 SECONDARY HEAT 1 LIMIT OPEN S21
- 520 FWM SOFTWARE MISMATCH
- 521 W4 STANDALONE
- 53 RESERVED
- 54 HEAT 1 S15 LIMIT OR ROLLOUT OPEN
- 55 STRIKE 3 HEAT 1 S15 LIMIT OR ROLLOUT
- 56 HEAT 1 CAI SWITCH S18
- 57 STRIKE 3 HEAT 1 CAI SWITCH S18
- 58 RESERVED
- 59 STRIKE 3 HEAT 1 NO PROOF GV1
- 6 DIRTY AIR FILTER
- 60 PRIMARY HEAT 2 LIMIT OPEN S99
- 61 STRIKE 3 PRIMARY HEAT LIMIT OPEN
- 62 SECONDARY HEAT 2 LIMIT OPEN S100
- 63 RESERVED
- 64 HEAT 2 CAI SWITCH S45
- 65 STRIKE3 HEAT 2 ROLL OUT OPEN
- 66 HEAT 2 CAI SWITCH S45
- 67 STRIKE 3 HEAT 2 CAI SWITCH S45
- 68 RESERVED
- 69 STRIKE 3 HEAT 2 NO PROOF GV3
- 7 RESERVED
- 70 - 72 RESERVED
- 73 NETWORK SENSOR
- 74 ZONE SENSOR
- 75 OUTDOOR TEMP SENSOR
- 76 HUMIDITY SENSOR
- 77 DISCHARGE AIR TEMP SENSOR
- 78 RETURN AIR TEMP SENSOR
- 79 ID ADD ON BOARD PROBLEM
- 8 STRIKE 3 ON BLOWER NO AIRFLOW
- 80 ID ADD ON BOARD PROBLEM
- 81 REHEAT SETUP ERROR
- 82 CONTROLLER RESET
- 83 - 84 RESERVED
- 85 INCORRECT HUMIDITROL
- 86 CONFLICTING TSTAT INPUT
- 87 - 90 RESERVED
- 9 - 11 RESERVED
- 91 OUTDOOR ENTHALPY SENSOR
- 92 INDOOR ENTHALPY SENSOR
- 93 UNIT OPERATING IN BACKUP MODE
- 94 ZONE SETPOINT ERROR
- 95 - 98 RESERVED
- 99 OUTSIDE AIR VELOCITY SENSOR ERROR
- A173 Smoke
- BUS (green) Flickering ON Network traffic present
- CE10 Cool + Modulate Economizer (10%)
- CEoP Cool + Max Open Economizer
- CO78 Cooling (78%)
- Eror Off On Alarm
- FAC Fresh Air Cooling
- FAh Fresh Air Heating
- FrCL Free Cooling
- Green Fast Flash Boot loader / firmware update mode
- Green Slow Flash Normal Operation
- Green Steady On Unit in configuration / test mode (not in normal mode)
- LoUt Controller Lockout
- PnSt Pre-Install
- PrCL Pre-Cool
- Prht Morning Warm-up
- ShEd Compressor Load Shedding
- Steady Off No voltage to M4 board or defective board
- Strt Start up
- TX (yellow) Flickering ON Unit controller is transmitting
- Yellow demand indication Yellow thermostat input indicates demand: G - Blower on
- b23 Blower On (23%)
- b71S Blower On - (71%) OAS
- d020 Delay up to 20 seconds
- d300 Delay up to 5 minutes
- dhUM Dehumidification
- h050 Heating (50%)
- idLE No Demand
- ioAS No Demand - OAS
Reference only. Confirm against the manual for your exact model. Data release 105f66ecb9e96e5dc473025d.