Hargassner Control — Home Assistant Integration

Bidirectional control of Hargassner pellet boiler systems via the Hargassner Connect cloud portal.

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⚠️ Works Best Alongside BauerGroup Hargassner Integration

This integration is CONTROL ONLY — it does not provide boiler sensor data.

For the full picture — 228 live sensors including temperatures, O₂ levels, pump states, buffer data, and boiler diagnostics — install the BauerGroup IP-HargassnerIntegration alongside this one:

🔗 github.com/bauer-group/IP-HargassnerIntegration

BauerGroup connects directly to the boiler via local telnet and provides the real-time sensor feed. This integration connects to the Hargassner Connect cloud portal and provides the write-back controls. Together they give you a complete integration.

What this integration does NOT do

• ❌ Does not provide boiler temperature, O₂, or exhaust sensors
• ❌ Does not provide flow / return temperature readings (Vorlauf / Rücklauf)
• ❌ Does not provide pump status or boiler operational state
• ❌ Does not provide buffer or domestic hot water temperature sensors
• ❌ Does not connect to the boiler directly — all control goes via the cloud portal

What this integration DOES do

• ✅ Sets the heating circuit mode (Automatic / Heating / Reduction / Off)
• ✅ Adjusts all heating parameters (room temps, steepness, deactivation limits)
• ✅ Controls solar mode and bathroom heating (Badewanne)
• ✅ Triggers force hot-water charge
• ✅ Updates pellet stock level
• ✅ Shows last sync timestamp and connection status
• ✅ Supports English and German (matches Hargassner API terminology)

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Features

• Control-only — 13 control entities (number, select, button) + 2 status sensors
• Auto-discovery — OAuth credentials extracted from live JS bundle; installation ID auto-detected
• Self-healing — re-extracts credentials on startup; auto-retries on 401
• Bilingual — full EN/DE translations using exact Hargassner portal terminology
• Zero config — enter only your email and password

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Requirements

• Home Assistant 2024.1 or later
• A Hargassner Connect account with your boiler registered
• Internet access from your HA host (outbound HTTPS to web.hargassner.at)
• BauerGroup IP-HargassnerIntegration recommended for sensor data

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Installation

Via HACS (recommended)

1. Open HACS → Integrations
2. Click the three-dot menu → Custom repositories
3. Add https://github.com/knirzinger/hargassner-ha with category Integration
4. Search for Hargassner Control and install
5. Restart Home Assistant

Manual

1. Copy the custom_components/hargassner_control/ folder into your HA config/custom_components/ directory
2. Restart Home Assistant

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Setup

1. Go to Settings → Devices & Services → Add Integration
2. Search for Hargassner Control
3. Enter your Hargassner Connect email and password
4. The integration auto-discovers your installation and connects

Credentials note: Only your email and password are stored. The OAuth client credentials are fetched from the Hargassner Connect web app on every startup — never hardcoded, never stored.

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Entities

Sensors (read-only, status only)

Entity	Description
sensor.last_sync	Timestamp of last successful data refresh
sensor.connection	Online / Offline connection status

Numbers (read + write)

Entity	EN Name	DE Name	Range	Step
number.room_temperature_correction	Temperature Correction	Temperatur Korrektur	−3 … +3 °C	0.5
number.room_temperature_heating	Room Temperature (Heating)	Raumtemperatur Heizen	10 … 30 °C	0.5
number.room_temperature_reduction	Room Temperature (Reduction)	Raumtemperatur Absenkung	10 … 30 °C	0.5
number.steepness	Heating Curve Steepness	Heizkurve Steilheit	0.2 … 3.5	0.05
number.deactivation_limit_heating	Heating Off Temp	Heizen Aus Temp	−10 … 30 °C	1.0
number.deactivation_limit_reduction_day	Day Setback Off Temp	Tagabsenkung Aus Temp	−10 … 30 °C	1.0
number.deactivation_limit_reduction_night	Night Setback Off Temp	Nachtabsenkung Aus Temp	−10 … 30 °C	1.0
number.pellet_stock	Pellet Stock	Pellets Lagerstand	0 … 5000 kg	10

Selects (read + write)

Entity	EN Name	DE Name	Options
select.heating_mode	Heating Mode	Heizkreis Modus	Automatic / Heating / Reduction / Off
select.solar_mode	Solar Mode	Solar Modus	On / Off
select.bathroom_heating	Bathroom Heating	Badewanne / Einmalladung	On / Off

Buttons (action)

Entity	EN Name	DE Name
button.force_charge	Force Hot Water Charge	Warmwasser Sofort Laden

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How It Works

All communication is outbound HTTPS from your HA host to web.hargassner.at. No inbound connections, no MQTT, no local LAN access to the boiler.

Home Assistant
  └─ HargassnerCoordinator (poll every 15 min)
       └─ HargassnerApiClient
            ├─ GET  /js/app.js                              → extract client_id + client_secret
            ├─ POST /oauth/token                            → ROPC Bearer token
            ├─ GET  /api/installations/{id}/widgets         → sync current settings
            ├─ PATCH /api/installations/{id}/widgets/…      → write parameter changes
            └─ POST  /api/installations/{id}/widgets/…      → trigger actions

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Automation Examples

Solar surplus — enable solar mode when inverter produces excess:

automation:
  - alias: "Hargassner solar on surplus"
    trigger:
      - platform: numeric_state
        entity_id: sensor.fronius_power_surplus
        above: 1500
    action:
      - service: select.select_option
        target:
          entity_id: select.hargassner_control_solar_mode
        data:
          option: MODE_ON

Badewanne (hot water boost):

automation:
  - alias: "Hargassner force charge"
    trigger:
      - platform: state
        entity_id: input_boolean.badewanne_active
        to: "on"
    action:
      - service: button.press
        target:
          entity_id: button.hargassner_control_force_charge

Guard room thermostats against summer mode:

condition:
  - condition: not
    conditions:
      - condition: state
        entity_id: select.hargassner_control_heating_mode
        state: MODE_OFF

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Troubleshooting

secret_extraction_failed during setup — The portal JS structure changed. Open a GitHub issue.

Entities show unavailable — Check Settings → System → Logs, filter for hargassner_control. Usually a network issue or portal maintenance. Connection sensor will show offline.

Values bounce back after write — The portal rejected the value (out of range). Check HA logs for HTTP status code.

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Known Limitations

• Heating circuit 1 only — multi-circuit installations (HK2, HK3) not yet supported
• All control via cloud — no local LAN API on the boiler itself
• ROPC OAuth grant — a legacy flow; may require updates if Hargassner migrate to auth code flow

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API Reference

Method	Endpoint	Description
GET	/js/app.js	Extract OAuth client_id + client_secret
POST	/oauth/token	Obtain Bearer token (ROPC)
GET	/api/installations/{id}/widgets	Read all controllable settings
PATCH	/api/installations/{id}/widgets/heating-circuits/1/parameters/{param}	Write heating circuit parameter
PATCH	/api/installations/{id}/widgets/heater/parameters/fuel-stock	Update pellet stock
PATCH	/api/installations/{id}/widgets/buffer/default/parameters/solar-mode-active	Set solar mode
POST	/api/installations/{id}/widgets/boilers/1/actions/force-charging	Force hot water charge

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Disclaimer

Developed by reverse-engineering network traffic from a legally owned Hargassner installation. No proprietary software was decompiled or modified. Use subject to Hargassner's terms of service. No warranty regarding API stability.

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License

MIT — see LICENSE file.

Author

Ronald Knirzinger