HVAC · supported

Mitsubishi Electric

ModbusBACnetREST

Mitsubishi Electric supplies City Multi VRF, M-Series splits, and Ecodan heat pumps across residential and light-commercial markets. HVAC API bridges Mitsubishi MELCloud and on-prem M-NET adapters to one HTTP surface for setpoint, mode, fan, and zone control.

Device families

City Multi VRF

3 endpoints
Ecodan Heat Pumps

2 endpoints

Endpoints & snippets

City Multi VRF

GET /v1/devices/{id}/temperature
POST /v1/devices/{id}/setpoint
POST /v1/devices/{id}/mode

curl -H "Authorization: Bearer $HVACAPI_KEY" \
  https://api.hvacapi.com/v1/devices/{device_id}/setpoint

Ecodan Heat Pumps

GET /v1/devices/{id}/temperature
GET /v1/devices/{id}/state

Fault codes & error codes

15 codes documented for Mitsubishi Electric. Confirm against your model's service manual — some codes vary between product lines (VRV vs. Sky Air vs. residential split, etc.).

15

Code	Category	Meaning	Suggested action	Severity	Help
E6	Outdoor unit	Compressor overcurrent (CT fault) Ask AI to troubleshoot →	Check compressor windings, refrigerant charge, and inverter current sensors.	critical	Ask AI →
E7	Outdoor unit	Outdoor fan motor overcurrent / lock Ask AI to troubleshoot →	Inspect fan motor for physical obstruction; check motor winding resistance.	critical	Ask AI →
E8	Outdoor unit	Input overcurrent (inverter / compressor) Ask AI to troubleshoot →	Check power-supply voltage, compressor, and inverter board.	critical	Ask AI →
E9	Outdoor unit	Expansion valve (LEV) fault Ask AI to troubleshoot →	Check LEV wiring harness and coil resistance; replace valve if coil is open.	critical	Ask AI →
P8	Indoor unit	Pipe temperature abnormal (superheat / subcool fault) Ask AI to troubleshoot →	Verify refrigerant charge, expansion valve operation, and pipe thermistors TH2/TH5.	critical	Ask AI →
U4	System	Indoor↔outdoor communication error (serial) Ask AI to troubleshoot →	Check M-NET transmission wiring polarity and termination; verify outdoor-unit PCB address switches.	critical	Ask AI →
U6	System	Compressor overcurrent during startup (soft-start fault) Ask AI to troubleshoot →	Inspect compressor windings and inverter board; verify refrigerant charge is not excessive.	critical	Ask AI →
P1	Indoor unit	Intake-air thermistor (TH1) open or shorted Ask AI to troubleshoot →	Check TH1 resistance and connector on the indoor PCB.	warning	Ask AI →
P2	Indoor unit	Pipe (liquid/liquid-gas) thermistor (TH2) fault Ask AI to troubleshoot →	Check TH2 connector and resistance; replace if out of spec.	warning	Ask AI →
P4	Indoor unit	Drain sensor fault or drain-up error Ask AI to troubleshoot →	Check float switch, drain pump, and drain piping for blockage.	warning	Ask AI →
P6	Indoor unit	Freeze-up protection activated (indoor coil) Ask AI to troubleshoot →	Check return-air filter, coil airflow, and refrigerant charge.	warning	Ask AI →
U2	System	Power-supply voltage abnormal (overvoltage / undervoltage) Ask AI to troubleshoot →	Measure supply voltage and verify it is within nameplate tolerance; check phase rotation on 3φ.	warning	Ask AI →
U5	System	Remote controller communication error Ask AI to troubleshoot →	Check MA Remote Controller wiring; ensure only one master controller per indoor unit.	warning	Ask AI →
U8	System	Outdoor-unit inter-unit communication error (multi-outdoor) Ask AI to troubleshoot →	Verify BC controller and inter-unit transmission wiring on multi-outdoor VRF systems.	warning	Ask AI →
U3	System	Outdoor unit charge check not completed Ask AI to troubleshoot →	Run the refrigerant charge check procedure per the commissioning manual.	info	Ask AI →

Mitsubishi Electric

Device families

Endpoints & snippets

Fault codes & error codes

External resources