90 fault, warning and safety-shutdown messages documented by the manufacturer for the YORK YLAA, from 8 manuals. A message in bold has a page of its own: what it means, why it appears, what to check and how the unit restarts — from the manual that documents it. The others link to their row in the manual, with the page it was taken from.
Troubleshooting
| Message on the display | What it means | Manual |
|---|---|---|
| NO DISPLAY ON PANEL. UNIT WILL NOT OPERATE. | 1. No 115VAC to 24 VAC Transformer. 2. No 24VAC to Microboard. 3. Control Transformer defective, no… | 150.72-NM1 p.174 |
| FLOW SWITCH/REM STOP NO RUN PERMISSIVE | 1. No chilled liquid flow. 2. Flow switch improperly installed. 3. Defective flow switch. 4. Remote… | 150.72-NM1 p.174 |
| LOW SUCTION PRESSURE FAULT | 1. Improper suction pressure cutouts adjustments. 2. Low refrigerant charge. 3. Fouled filter… | 150.72-NM1 p.174 |
| HIGH DISCHARGE PRESSURE FAULT | 1. Condenser fans not operating or operating backwards. 2. Too much refrigerant. 3. Air in… | 150.72-NM1 p.174 |
| LOW LIQUID TEMP FAULT | 1. Improperly adjusted leaving chilled liquid temp. cutout (glycol only). 2. Micro panel… | 150.72-NM1 p.175 |
| MP / HPCO FAULT | 1. Compressor internal motor protector (MP) open. 2. External overload tripped. 3. HPCO switch… | 150.72-NM1 p.175 |
| COMPRESSOR(S) WON'T START | 1. Demand not great enough. 2. Defective water temperature sensor. 3. Contactor/Overload failure.… | 150.72-NM1 p.175 |
| LACK OF COOLING EFFECT | 1. Fouled evaporator surface. Low suction pressure will be observed. 2. Improper flow through the… | 150.72-NM1 p.175 |
| NO DISPLAY ON PANEL. UNIT WILL NOT OPERATE | 1. No 115 VAC to 24 VAC Transformer. 2. No 24 VAC to Microboard. 3. Control Transformer defective,… | 150.72-ICOM7 p.179 |
| COMPRESSORS WON'T START | 1. Demand not great enough. 2. Defective water temperature sensor. 3. Contactor/Overload failure.… | 150.72-ICOM7 p.180 |
Real Time Error Numbers
| Message on the display | What it means | Manual |
|---|---|---|
| REAL TIME ERROR 1 | DATUM TYPE OK TEST FAILED | 150.72-NM2 p.182 |
| REAL TIME ERROR 2 | ENGLISH TEXT TOO LONG | 150.72-NM2 p.182 |
| REAL TIME ERROR 3 | FLOATING POINT EXCEPTION | 150.72-NM2 p.182 |
| REAL TIME ERROR 4 | GET PACKET FAILED | 150.72-NM2 p.182 |
| REAL TIME ERROR 5 | GET TYPE FAILED | 150.72-NM2 p.182 |
| REAL TIME ERROR 6 | INVALID UNIT CONVERSION | 150.72-NM2 p.182 |
| REAL TIME ERROR 7 | INVALID HARDWARE SELECTION | 150.72-NM2 p.182 |
| REAL TIME ERROR 8 | REAL TIME FAULT | 150.72-NM2 p.182 |
| REAL TIME ERROR 9 | SPANISH TEXT TOO LONG | 150.72-NM2 p.182 |
| REAL TIME ERROR 10 | THREAD EXITED | 150.72-NM2 p.182 |
| REAL TIME ERROR 11 | THREAD FAILED | 150.72-NM2 p.182 |
| REAL TIME ERROR 12 | THREAD STALLED | 150.72-NM2 p.182 |
| REAL TIME ERROR 13 | IO BOARD RESET | 150.72-NM2 p.182 |
| REAL TIME ERROR 14 | BRAM INVALID | 150.72-NM2 p.182 |
| REAL TIME ERROR 15 | BACNET SETUP FAILED | 150.72-NM2 p.182 |
System Safeties
| Message on the display | What it means | Manual |
|---|---|---|
| SYS 1 HIGH DSCH PRES SYS 2 HIGH DSCH PRES | The Discharge Pressure Cutout is a software cutout in the microprocessor and is backed-up by a… | 150.72-ICOM7 p.118 |
| SYS 1 LOW SUCT PRESS SYS 2 LOW SUCT PRESS | The Suction Pressure Cutout is a software cutout that helps protect the chiller from an evaporator… | 150.72-ICOM7 p.169 |
| SYS 1 MP/HPCO FAULT SYS 2 MP/HPCO FAULT | Motor Protector/Mechanical High Pressure Cutout - protects the compressor motor from overheating or… | 150.72-ICOM7 p.168 |
| SYS 1 MP/HPCO INHIB SYS 2 MP/HPCO INHIB | Motor Protector/High Pressure Inhibit - displayed while the internal compressor contacts are open… | 150.72-ICOM7 p.168 |
| SYS 1 HIGH MTR CURR SYS 2 HIGH MTR CURR | With the System Current Feedback option installed and selected (Current Feedback option under the… | 150.72-ICOM7 p.118 |
| Sensor Failure (EEV) | This safety shuts down a system if either suction temperature or suction pressure sensors read out… | 150.72-ICOM7 p.112 |
| SYS 1 SP/ FREEZE WARN SYS 2 SP/ FREEZE WARN | Suction pressure / freeze warning - transient protection routine active | 150.72-ICOM6 p.145 |
| SYS 1 LOW SUPERHEAT SYS 2 LOW SUPERHEAT | System Fault Code 23 - Low Suction Superheat cutout (EEV mode only); also displayed as “SYS x LOW… | 150.72-ICOM6 p.145 |
| SYS 1 SENSOR FAILURE SYS 2 SENSOR FAILURE | System Fault Code 24 - Sensor Failure cutout (EEV mode only) | 150.72-ICOM6 p.145 |
| LOW EVAPORATOR TEMPERATURE (R407c ONLY - N/A HP HEATING MODE) | System Fault Code 19 - Low Evaporator Temperature (R407c only; not applicable in heat pump heating… | 150.72-ICOM6 p.144 |
| DISCHARGE INHIBIT (HEAT PUMP HEATING MODE ONLY) | System Fault Code 25 - Discharge Inhibit (heat pump heating mode only) | 150.72-ICOM6 p.144 |
Unit Safeties
| Message on the display | What it means | Manual |
|---|---|---|
| UNIT FAULT: LOW AMBIENT TEMP | The Low Ambient Temp Cutout is a safety shutdown designed to protect the chiller from operating in… | 150.72-ICOM7 p.112 |
| UNIT FAULT: LOW LIQUID TEMP | The Low Leaving Chilled Liquid Temp Cutout protects the chiller from an evaporator freeze-up should… | 150.72-ICOM7 p.112 |
| UNIT FAULT: 115VAC UNDERVOLTAGE | The Under Voltage Safety ensures that the system is not operated at voltages where malfunction of… | 150.72-ICOM7 p.110 |
| UNIT FAULT: HIGH MTR CURR | With the CURRENT FEEDBACK ONE PER UNIT option selected under the OPTIONS key, the unit shuts down… | 150.72-ICOM7 p.112 |
| FLOW SWITCH OPEN | Indicates the flow switch contacts connected to Terminals 13 and 14 of XTBC1 are open. | 150.72-ICOM7 p.107 |
| UNIT FAULT: CHECK LIQ TEMP SENS | Check Liquid Temperature Sensor fault (unit fault) | 150.72-ICOM6 p.141 |
| UNIT FAULT: PUMP TRIP | Unit Fault Code 27 - Pump Trip (Hydro Pumps 1 or Hydro Pumps 2) | 150.72-ICOM6 p.144 |
| UNIT FAULT: PUMP FAIL MAKE FLOW | Unit Fault Code 28 - Pump Flow Failure (Hydro Pumps 1 or Hydro Pumps 2) | 150.72-ICOM6 p.141 |
| UNIT FAULT: 115 VAC UNDER VOLTAGE | Under Voltage Safety (unit fault) | 150.72-ICOM6 p.141 |
Unit Warning
| Message on the display | What it means | Manual |
|---|---|---|
| !! LOW BATTERY !! CHECK PROG/SETP/OPTN | Unit warning - not a unit safety, not logged to the history buffer, and will not auto-restart;… | 150.72-ICOM7 p.113 |
| INCORRECT UNIT TYPE | Unit warning - not a unit safety, not logged to the history buffer, and will not auto-restart;… | 150.72-ICOM7 p.113 |
Fault/Inhibit Code Names (Native BACnet, Modbus, and N2 Communications Data Map)
| Message on the display | What it means | Manual |
|---|---|---|
| Unit Fault Low Leaving Chilled Liquid Temperature | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| High Discharge Pressure | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Low Ambient Temperature | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| System Fault | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Low Suction Pressure | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Unit Motor Current | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Low Superheat | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Sensor Fault | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Discharge Inhibit | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| MP/HPCO Inhibit | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| MP/HPCO Fault | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Leaving Chilled Liquid Temperature Sensor Fault | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Pump Trip | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Pump Fail Make Flow | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| High Ambient Temperature | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Anti-Vacuum Low Pressure Cutout | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
| Low Evaporator Temperature | Fault/inhibit code name in the Native BACnet, Modbus, and N2 communications data map (reported via… | 150.72-ICOM7 p.147 |
Flash Card Update Error
| Message on the display | What it means | Manual |
|---|---|---|
| FLASH CARD UPDATE ERROR | Displayed, with the error code, if an error occurred during a Flash Card software update; no reboot… | 150.72-ICOM7 p.136 |
System Inhibits
| Message on the display | What it means | Manual |
|---|---|---|
| SYS 1 ATV SUCT PRESS SYS 2 ATV SUCT PRESS | System Inhibit Code 30 - Anti-Vacuum Low Pressure Cutout | 150.72-ICOM6 p.143 |
| SYS 1 LOW DS CH SHE AT SYS 2 LOW DS CH SHE AT | System Inhibit Code 33 - Low Discharge Superheat | 150.72-ICOM6 p.145 |
Verify Fan Operation and Programming
| Message on the display | What it means | Manual |
|---|---|---|
| LED on the electronic module flashes 11 times | The initialization process failed. | SI0601 p.4 |
ABB AYK550 VFD Drive Not Responding Fault
| Message on the display | What it means | Manual |
|---|---|---|
| Drive not responding | Fault appearing on the screen for the ABB AYK550 Variable Frequency Drive (VFD) installed on… | SI0466 p.1 |
Fault Code (Red LED color)
| Message on the display | What it means | Manual |
|---|---|---|
| Phase failure (Red LED, 1 pulse) | Automatic restart once phase failure is corrected | SI0487 p.4 |
| Power module overheated (Red LED, 3 pulses) | Power cycle required | SI0487 p.4 |
| Internal communications error between primary/secondary controller (Red LED, 4 pulses) | Primary = electronics, Secondary = motor | SI0487 p.4 |
| Motor overheated (Red LED, 6 pulses) | Power cycle required | SI0487 p.4 |
| Hall sensor error (Red LED, 7 pulses) | Power cycle required | SI0487 p.4 |
| Motor blocked (Red LED, 8 pulses) | Automatic restart after blockage is cleared | SI0487 p.4 |
| Speed limit exceeded (Red LED, 9 pulses) | Automatic restart | SI0487 p.4 |
| Rotor position sensor calibration error (Red LED, 11 pulses) | Power cycle required | SI0487 p.4 |
| DC-link undervoltage (Red LED, 13 pulses) | Automatic restart after undervoltage is cleared | SI0487 p.4 |
Fault Code (Yellow LED color)
17 of 90 messages have a page of their own. Other documentation for this model: commissioning and checklists · installation · parts lists · service bulletins · specifications · wiring diagrams. All YORK models: YORK manuals.