activeFaults arrays on device objects (HCU, Heat Pump, FCU, Sensor). Each code is a 4-character alphanumeric identifier indicating a specific fault condition.
HCU Faults (Process & Flow)
Codes relating to hydraulic integrity, flow delivery, and system integration.| Code | Name | Description |
|---|---|---|
E001 | Water Inlet Sensor Failure | Inlet temperature sensor open or shorted |
E002 | Water Outlet Sensor Failure | Outlet temperature sensor open or shorted |
E003 | Flow Switch Failure | Flow switch malfunctioning or disconnected |
E004 | Flow Protection | Insufficient water flow during operation |
E100 | Outdoor Communication Failure | Cannot communicate with outdoor heat pump |
E101 | Indoor Communication Failure | Internal communication failure with hydronic board |
E201 | Defrost Failure | Three unsuccessful defrost attempts; operation stopped |
E202 | Outlet Temp High (Heat) | Water temp exceeded safety limits in heating mode |
E203 | Outlet Temp Low (Cool) | Water temp below safety limits in cooling mode |
E204 | Outlet Temp Low (Heat/DHW) | Cannot reach target temp; possible capacity issue |
E205 | Anti-Freeze Protection | Emergency circulation to prevent pipe freezing |
Heat Pump Faults
Codes specific to heat pump hardware, populated whensource_type = heat_pump.
Sensors
| Code | Name | Description |
|---|---|---|
E010 | Ambient Temp Sensor Fault | Outdoor air temperature sensor failure |
E011 | Coil Temp Sensor Fault | Refrigerant coil temperature sensor failure |
E012 | Discharge Temp Sensor Fault | Compressor discharge temp sensor failure |
E013 | Suction Temp Sensor Fault | Compressor suction temp sensor failure |
E014 | High Pressure Sensor Fault | Refrigerant high-pressure sensor failure |
E015 | Low Pressure Sensor Fault | Refrigerant low-pressure sensor failure |
E102 | Driver Communication Fault | Lost communication with compressor inverter |
E103 | EEPROM Failure | Critical memory error on controller board |
Electrical
| Code | Name | Description |
|---|---|---|
P001 | AC Input Over-Voltage | Supply voltage exceeded upper limit |
P002 | AC Input Under-Voltage | Supply voltage below lower limit |
P003 | AC Input Over-Current | Current draw exceeded system rating |
P004 | Input Phase Error | Missing phase or incorrect sequence |
P005 | DC Bus Over-Voltage | Internal DC bus voltage too high |
P006 | DC Bus Under-Voltage | Internal DC bus voltage too low |
P007 | PFC Hardware Fault | Power Factor Correction module failure |
Refrigerant
| Code | Name | Description |
|---|---|---|
P101 | High Pressure Protection | High-pressure switch tripped |
P102 | Low Pressure Protection | Low-pressure switch tripped; possible leak |
P103 | Discharge Temp High | Discharge gas temp exceeded limit |
P104 | Oil Return Protection | Oil return cycle triggered |
P105 | 4-Way Valve Failure | Reversing valve stuck or failed |
Compressor
| Code | Name | Description |
|---|---|---|
P201 | IPM Module Protection | Inverter module detected a fault |
P202 | IPM Over-Heat | Inverter module temperature too high |
P203 | Compressor Phase Error | Open phase or winding imbalance |
P204 | Compressor Over-Current | Compressor current exceeded limits |
P205 | Compressor Stall | Compressor failed to start or stalled |
P206 | Fan Motor Failure | DC fan motor failed or not reporting speed |
P207 | Driver Failure | Compressor driver board failure |
FCU Faults
Codes for fan coil unit hardware and process issues.| Code | Name | Description |
|---|---|---|
F010 | Airflow Fault | Fan failed to start or insufficient airflow |
F011 | Condensate / Drain Fault | Condensate pan full or drain blocked |
F012 | Coil Temp Sensor Fault | Coil temperature sensor open/short |
F013 | Comm Fault (Local) | Internal FCU communication failure |
F014 | FCU Communication Lost | Brain lost contact with FCU (auto-clears) |
Sensor Faults
Codes for standalone sensors and system-level threshold violations.| Code | Name | Description |
|---|---|---|
S001 | Sensor Communication Lost | No data from sensor within expected window |
S002 | Sensor Reading Invalid | Value outside physically possible range |
S100 | System Pressure Critical Low | Below 0.75 bar; likely major leak |
S101 | System Pressure Warning Low | 0.75-1.0 bar; possible slow leak |
S102 | System Pressure Warning High | 1.4-1.7 bar; check expansion vessel |
S103 | System Pressure Critical High | Above 1.7 bar; PRV may trigger |
S200 | Disk Space Critical | Storage below 5% free |
S201 | Disk Space Warning | Storage below 10% free |
Legionella Faults
Codes for DHW sanitization cycles.| Code | Name | Description |
|---|---|---|
L001 | Sanitization Timeout | DHW tank did not reach 60C within 3 hours |