Tasmota MiElHVAC Integration for Home Assistant

This integration automatically discovers and creates climate entities for your HVAC devices, seamlessly linking them to your existing Tasmota devices.

• 🔍 Automatic Discovery - Detects MiElHVAC devices via MQTT automatically
• 🔗 Device Linking - Climate entities appear under your Tasmota devices
• 🌡️ Full Climate Control - Temperature, modes, fan speed, and swing control
• 🏠 Local Control - All communication via local MQTT (no cloud required)
• 🔄 State Persistence - Remembers settings after Home Assistant restarts
• 🌍 Multi-language - English and French UI translations included
• ⚡ Energy Monitoring - Real-time power (W) and cumulative energy (kWh)
• 🌬️ Extended Controls - Purifier, Night Mode, EconoCool, i-See Air Direction
• 🌡️ Remote Temperature - Send an external temperature sensor reading to the unit
• 📊 Capability Awareness - Exposes unit capabilities reported by the driver
• ↔️ Backward Compatible - Works with both legacy and new Tasmota MiElHVAC driver

• Off
• Auto
• Cool
• Dry
• Heat
• Fan Only

• Auto
• Quiet
• Speed 1–4

• Vertical: Auto, Up, Up-Middle, Center, Down-Middle, Down, Swing
• Horizontal: Auto, Left, Left-Middle, Center, Right-Middle, Right, Swing

• Range: 10°C – 31°C (may be narrowed by unit capabilities)
• Precision: 0.5°C steps

These features are exposed as state attributes and callable via Home Assistant services. They are only available when your Tasmota firmware reports the corresponding capability (cap_run_state=true):

• ESP32 or ESP8266 device running Tasmota
• Mitsubishi Electric heat pump with CN105 connector
• JST PA 5-pin connector (2.0mm pitch) to interface with CN105

For complete hardware setup including wiring diagrams and CN105 pinout, see:

• Integration with Home Assistant via Tasmota (Archive)
• Hacking A Mitsubishi Heat Pump Part 1

• Home Assistant 2023.1 or newer
• Tasmota firmware with MiElHVAC driver enabled
  • Pre-compiled Tasmota32 firmware available at MiElHVAC Tasmota Display Driver
  • Or compile your own using TasmoCompiler with #define USE_MIEL_HVAC
• MQTT broker (e.g., Mosquitto) configured in Home Assistant

Note: This Home Assistant integration works with both ESP32 and ESP8266. The MiElHVAC Display Driver (Berry-based web UI) requires ESP32 only, but is optional.

This integration is compatible with all versions of the Tasmota MiElHVAC driver:

Your Tasmota device must:

1. Have MiElHVAC driver active

   • The driver should publish HVAC data to tele/{topic}/SENSOR

2. Be connected to your MQTT broker

   • Same broker as Home Assistant

3. Have discovery enabled (recommended)

   SetOption19 0
   

4. Have a configured Device Name

   • Set in Tasmota: Configuration → Configure Other → Device Name
   • Example: "Living Room AC" or "Bedroom HVAC"

1. Open HACS in Home Assistant
2. Click on Integrations
3. Click the three dots menu (top right) → Custom repositories
4. Add repository:
   • URL: https://github.com/aldweb/ha-tasmota-mielhvac
   • Category: Integration
5. Click Add
6. Search for "Tasmota MiElHVAC" in HACS
7. Click Download
8. Restart Home Assistant

1. Download the latest release from GitHub
2. Extract the tasmota_mielhvac folder
3. Copy it to your Home Assistant custom_components directory:

   config/
   └── custom_components/
       └── tasmota_mielhvac/
   

4. Restart Home Assistant

1. Go to Settings → Devices & Services
2. Click + Add Integration
3. Search for "Tasmota MiElHVAC"
4. Click on it and follow the setup dialog
5. Click Submit

That's it! No configuration needed - the integration will automatically discover your devices.

Check the logs to confirm your devices were discovered:

Settings → System → Logs

Look for messages like:

Discovered MiElHVAC device: tasmota_hvac (RoomTemp: 21.5°C) - Living Room AC

Go to Settings → Devices & Services → MQTT

Your Tasmota devices should now have a climate entity (HVAC) alongside their other entities.

Once discovered, you can control your HVAC through:

1. Lovelace UI - Use the standard Thermostat card
2. Home Assistant App - Full mobile control
3. Automations - Create climate-based automations
4. Voice Assistants - Control via Alexa, Google Assistant, etc.

Features like Purifier, Night Mode, EconoCool, Air Direction, and Remote Temperature are not yet exposed as native HA climate controls, but can be triggered via the mqtt.publish service or automations.

Send an external temperature reading to the HVAC unit (replaces the unit's built-in sensor):

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetRemoteTemp
  payload: "21.5"

To clear the remote temperature and revert to the unit's own sensor:

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetRemoteTempClearTime
  payload: "0"

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetPurify
  payload: "on"

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetNightMode
  payload: "on"

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetEconoCool
  payload: "on"

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetAirDirection
  payload: "swing"   # auto | swing | even | direct

service: mqtt.publish
data:
  topic: cmnd/your_topic/HVACSetSwingH
  payload: "swing"   # auto | left | left_middle | center | right_middle | right | swing

automation:
  - alias: "Send remote temperature to HVAC"
    trigger:
      - platform: state
        entity_id: sensor.living_room_temperature
    action:
      - service: mqtt.publish
        data:
          topic: cmnd/living_room_hvac/HVACSetRemoteTemp
          payload: "{{ states('sensor.living_room_temperature') }}"

automation:
  - alias: "HVAC Night Mode"
    trigger:
      - platform: time
        at: "22:30:00"
    action:
      - service: mqtt.publish
        data:
          topic: cmnd/bedroom_hvac/HVACSetNightMode
          payload: "on"

Note: HVACSetRemoteTemp and HVACSetRemoteTempClearTime replace the legacy HVACRemoteTemp / HVACRemoteTempClearTime commands from the pre-PR#24496 driver. The new driver (post-PR#24496) uses the HVACSet* prefix for all write commands.

Check these items:

1. MQTT Connection

   • Verify Tasmota is connected to MQTT broker
   • Check MQTT broker logs for messages from your device

2. MiElHVAC Data

   • Use MQTT Explorer to check if tele/{topic}/SENSOR contains MiElHVAC data
   • The payload should include at least one of: Temperature (legacy) or RoomTemperature (new driver)

3. Home Assistant Logs

   • Check for discovery messages or errors
   • Look for "Discovered MiElHVAC device" or error messages

4. Tasmota Device Name

   • Set a unique Device Name in Tasmota configuration
   • Restart Tasmota after changing the name

Purifier, Night Mode, EconoCool and Air Direction require:

1. A recent Tasmota build incorporating PR#24660 or later
2. A unit that supports run-state control (cap_run_state=true in the capabilities attribute)

Check the capabilities attribute of your climate entity to see what your unit supports.

This usually happens if Tasmota discovery is disabled.

Solution:

In Tasmota console, run:

SetOption19 0
Restart 1

1. Check MQTT topics in logs

   • Verify commands are being published

2. Test manually in Tasmota

   • In Tasmota console, try: HVACSetTemp 22
   • If this doesn't work, the issue is with the Tasmota driver, not this integration

3. Verify device is online

   • Check LWT status in MQTT Explorer: tele/{topic}/LWT should be "Online"

If you see duplicate climate entities:

1. Remove all duplicate entities via UI
2. Restart Home Assistant
3. The integration will recreate them correctly

For an enhanced Tasmota web interface with interactive controls (temperature adjustment, mode/fan/swing selectors), check out the companion Berry driver:

MiElHVAC Tasmota Display Driver

This optional Berry script adds a full-featured web UI directly in your Tasmota interface. Note: Requires ESP32 (Berry scripting not available on ESP8266).

Device names come from Tasmota's "Device Name" setting. To customize:

1. In Tasmota web UI: Configuration → Configure Other
2. Set Device Name to your preferred name
3. Restart Tasmota
4. In Home Assistant, remove and recreate the integration

If your HVAC unit's built-in sensor is inaccurate (common when the unit is behind furniture or in a corner), you can feed it a more accurate external reading via an automation. The driver will use this value instead of its own sensor until the timeout expires.

automation:
  - alias: "Sync external temperature to HVAC"
    trigger:
      - platform: state
        entity_id: sensor.living_room_temp
    action:
      - service: mqtt.publish
        data:
          topic: cmnd/living_room_hvac/HVACSetRemoteTemp
          payload: "{{ states('sensor.living_room_temp') }}"

┌─────────────────┐
│  Tasmota Device │
│  (ESP + HVAC)   │
└────────┬────────┘
         │ MQTT
         │
┌────────▼────────────────────┐
│    MQTT Broker              │
│    (Mosquitto)              │
└────────┬────────────────────┘
         │
    ┌────┴────┐
    │         │
┌───▼───┐ ┌──▼──────────────┐
│Tasmota│ │Tasmota MiElHVAC │
│Integr.│ │   Integration   │
└───┬───┘ └──┬──────────────┘
    │        │
    └───┬────┘
        │
┌───────▼──────────┐
│  Home Assistant  │
│  Climate Entity  │
└──────────────────┘

1. Tasmota publishes device info to tasmota/discovery/{MAC}/config
2. Integration caches device MAC address and name
3. Tasmota publishes HVAC data to tele/{topic}/SENSOR
4. Integration detects MiElHVAC data (any of the known field names)
5. Climate entity is created and linked to Tasmota device via MAC address
6. Entity appears under the Tasmota device in Home Assistant

Temperature Updates:

• Tasmota publishes current temp every TelePeriod (default 5 minutes)
• Integration updates Home Assistant immediately

Commands:

• User changes setting in Home Assistant
• Integration publishes MQTT command
• Tasmota sends command to HVAC
• Tasmota publishes new state
• Home Assistant updates entity

The integration handles both legacy and new driver payload formats transparently. Field name changes introduced by the Tasmota driver between 2024 and 2026 are resolved using fallback lookups:

No configuration change is needed when upgrading your Tasmota firmware.

• Installation Guide - Detailed setup instructions
• Technical Documentation - Architecture details
• Examples - MQTT examples and testing

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Home Assistant Community: Forum Thread

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request

This project is licensed under the MIT License - see the LICENSE file for details.

• MiElHVAC Tasmota Display Driver - Berry script for web UI controls and display

• Home Assistant - Open source home automation
• Tasmota - ESP firmware with MiElHVAC driver
• SwiCago - Original Mitsubishi protocol reverse engineering

• Created by @aldweb
• Inspired by the Tasmota and Home Assistant communities

Driver compatibility updated to cover all Tasmota MiElHVAC driver changes merged between February and April 2026 (PRs #24486, #24488, #24490, #24496, #24517, #24660). Full backward compatibility with the pre-PR#24486 driver is maintained.

New features:

• Energy monitoring: power_usage_w and energy_total_kwh state attributes (PR#24486)
• Extended run-state controls: Purifier, Night Mode, EconoCool, i-See Air Direction (PR#24660)
• Remote temperature: send an external sensor reading to the HVAC unit (PR#24517)
• Outdoor temperature attribute (PR#24517 / #24660)
• Unit capabilities exposed as capabilities attribute (PR#24660)

Breaking changes in Tasmota driver (handled transparently by this integration):

• HVACSETTINGS.Temp renamed to HVACSETTINGS.SetTemperature (PR#24490)
• SENSOR.MiElHVAC.Temperature renamed to SENSOR.MiElHVAC.RoomTemperature (PR#24490)
• SENSOR.MiElHVAC.Power (string) renamed to SENSOR.MiElHVAC.PowerState (PR#24490)
• HVACRemoteTemp command renamed to HVACSetRemoteTemp (PR#24496)
• HVACRemoteTempClearTime renamed to HVACSetRemoteTempClearTime (PR#24496)

• Initial public release
• Automatic device discovery via Tasmota MQTT discovery
• Full climate control support
• Device linking to existing Tasmota devices
• Multi-language UI (English, French)
• HACS compatible

Enjoy your automated climate control! 🌡️❄️🔥