Hargassner Pellet Boiler Integration - Project Summary

Overview

Complete, professional Home Assistant custom component for Hargassner pellet boilers with telnet interface. Built from scratch using modern best practices.

Version: 0.3.1 Status: Production Ready License: MIT

Key Features

✅ Real-time Monitoring - Continuous telnet data stream ✅ Auto-Reconnect - Exponential backoff, never gives up ✅ Thread-Safe - Async/await architecture ✅ Robust Encoding - UTF-8, Latin-1, CP1252 support ✅ GUI Configuration - Config Flow with validation ✅ Multi-Firmware - Supports multiple boiler versions ✅ Energy Dashboard - Built-in energy sensor (kWh) ✅ Bilingual - English and German translations ✅ Error Tolerant - Graceful degradation, extensive error handling ✅ Professional Docs - Architecture, development, contributing guides

Project Structure

./
├── custom_components/bauergroup_hargassnerintegration/    # Main integration
│   ├── __init__.py                         # Entry point, setup/teardown
│   ├── config_flow.py                      # GUI configuration
│   ├── const.py                            # Constants
│   ├── coordinator.py                      # Data coordinator
│   ├── manifest.json                       # HA integration metadata
│   ├── sensor.py                           # Sensor platform
│   ├── src/                                # Core business logic
│   │   ├── __init__.py
│   │   ├── firmware_templates.py           # XML templates for firmware versions
│   │   ├── message_parser.py               # Telnet message parser
│   │   └── telnet_client.py                # Thread-safe telnet client
│   └── translations/                       # Localization
│       ├── en.json
│       └── de.json
├── docs/                                   # Documentation
│   ├── ARCHITECTURE.md                     # Technical architecture (in-depth)
│   ├── CONTRIBUTING.md                     # Contribution guidelines
│   ├── DEVELOPMENT.md                      # Developer setup & workflow
│   └── INSTALLATION.md                     # End-user installation guide
├── tests/                                  # Unit tests (starter)
│   └── test_message_parser.py
├── .gitignore                              # Git ignore patterns
├── LICENSE                                 # MIT License
├── PROJECT_SUMMARY.md                      # This file
└── README.md                               # Main project README

Total: 18 files

Technical Architecture

Layer 1: Telnet Client (`src/telnet_client.py`)

Responsibilities:

Persistent telnet connection (port 23)
Background asyncio task for continuous receiving
Automatic reconnection with exponential backoff (5s → 300s)
Multi-encoding support (UTF-8, Latin-1, CP1252)
Thread-safe data storage with asyncio.Lock
Statistics tracking (messages, errors, reconnections)

Key Methods:

async_start() - Start client and background receiver
async_stop() - Graceful shutdown
get_latest_data() - Thread-safe data access
_receiver_loop() - Background message receiver
_process_data() - Encoding detection and parsing

Layer 2: Message Parser (`src/message_parser.py`)

Responsibilities:

Parse XML firmware templates
Extract values from telnet messages
Type conversion (float, int, bool)
Digital parameter bit extraction

Key Classes:

HargassnerMessageParser - Main parser
ParameterDefinition - Individual parameter metadata

Supported Message Format:

pm <val0> <val1> <val2> ... <valN>
   ^^^^^ Space-separated values

Layer 3: Coordinator (`coordinator.py`)

Responsibilities:

Bridge between telnet client and Home Assistant
Periodic data refresh (5 seconds)
Extends DataUpdateCoordinator for HA integration
Error handling and recovery

Layer 4: Sensor Platform (`sensor.py`)

Sensor Types:

Connection Sensor - Connection status + statistics
State Sensor - Boiler operating state (enum)
Error Sensor - Error messages (enum)
Parameter Sensors - Individual measurements
Energy Sensor - kWh calculation from pellet consumption

Sensor Sets:

STANDARD - 27 sensors (4 automatic + 23 parameters)
FULL - All sensors from firmware template (varies by version)

Layer 5: Configuration (`config_flow.py`)

Features:

GUI-based setup (Config Flow)
Connection validation before entry creation
Options flow for runtime changes
Unique ID validation (one entry per IP)

Data Flow

Boiler (Telnet Port 23)
    ↓ "pm 7 10.1 9.0 67.4 ..."
TelnetClient._receiver_loop()
    ↓ Decode (UTF-8/Latin-1/CP1252)
    ↓ Extract lines, find latest "pm" message
MessageParser.parse_message()
    ↓ Split values, map to parameters
    ↓ Type conversion, bit extraction
TelnetClient._latest_data (async locked)
    ↓ Poll every 5 seconds
Coordinator._async_update_data()
    ↓ Update event
Sensor Entities (Connection, State, Parameters, Energy)
    ↓ Display in Home Assistant UI

Firmware Support

Currently supported firmware versions:

V14_1HAR_q1 - 112 analog + many digital parameters

Adding new versions: Just add XML template to firmware_templates.py

Example Telnet Message (V14_1HAR_q1)

pm 7 10.1 9.0 67.4 70 64.5 65 11 91.3 26 27.0 62.3 59.3 58.7 89 5 64 3 70 62 30 28.9 30 100 30.0 30.0 29 96.0 100 3 0 0 18 2 10 0 0 333 324 160 24 1 21 0 91 8.00 12.99 616 8.9 24209 140.0 110.3 28 -20.0 -20.0 0.0 60.0 -20.0 93.4 1 0 -20.0 0 20.0 20.0 0 1 0 120.0 0 20.0 20.0 0 1 0 120.0 0 20.0 20.0 0 1 0 -20.0 0 20.0 20.0 0 1 0 -20.0 0 120.0 0 -20.0 0 0.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00 E 21 0 0 2007 0 0 0

This message contains 138 values corresponding to:

values[0] = ZK (Boiler state) = 7
values[3] = TK (Boiler temp) = 67.4°C
values[8] = TRG (Smoke gas temp) = 91.3°C
values[14] = Leistung (Output) = 89%
values[20] = Taus (Outside temp) = 30°C
... and so on

Error Handling

Connection Errors

Initial failure: Raises ConfigEntryNotReady, HA retries
Runtime loss: Background task continues reconnecting
Exponential backoff: 5s → 10s → 20s → ... → 300s max

Parsing Errors

Invalid encoding: Try UTF-8 → Latin-1 → CP1252 → fallback
Length mismatch: Log warning, parse available data
Invalid values: Return None, sensor shows "unknown"

Update Errors

No data yet: Return empty dict (not an error on startup)
Coordinator timeout: Automatic retry with backoff

Performance

Update interval: 5 seconds (configurable)
Memory usage: ~5-10 MB (typical)
CPU usage: Minimal (async I/O)
Network: ~1-2 KB/message, ~400 bytes/s average

Installation

Via HACS

Add custom repository
Install integration
Restart HA
Add via UI

Manual

Copy custom_components/hargassner_pellet to HA config
Restart HA
Add integration via Settings → Devices & Services

Configuration Example

# Via GUI (recommended), or YAML:
hargassner_pellet:
  host: 192.168.1.100
  firmware: V14_1HAR_q1
  device_name: Hargassner Boiler
  language: EN
  sensor_set: STANDARD
  pellet_energy_kwh_per_kg: 4.8  # Pellet energy content (3.0-6.0)
  efficiency_percent: 90          # Boiler efficiency (50-100)

Available Sensors (Standard Set - 27 Sensors)

Automatic Sensors (4):

Connection Status
Boiler State (Off/Ignition/Full Firing/etc.)
Operation Status (OK/Errors)
Heat Output (kWh) - Calculated from pellet consumption

Boiler & Combustion (8):

Boiler Temperature (TK)
Boiler Setpoint (TKsoll)
Flue Gas Temperature (TRG)
Burner Temperature (BRT)
Output Power (Leistung)
Efficiency (Effizienz)
O2 Level (O2)
Draft Actual (SZist)

Buffer & Storage (6):

Buffer Top/Middle/Bottom (TPo, TPm, TPu)
Buffer Fill Level (Puff Füllgrad)
Buffer Setpoint Top/Bottom (Puffer_soll oben/unten)

Heating Circuits (3):

Flow Temperature HC1 (TVL_1)
Flow Setpoint HC1 (TVLs_1)
Return Temperature (TRL)

Hot Water (2):

Hot Water Temperature (TB1)
Hot Water Setpoint (TBs_1)

Outside & Pellets (3):

Outside Temperature (Taus)
Pellet Stock (Lagerstand)
Pellet Consumption (Verbrauchszähler)

Energy Dashboard Integration

Energy sensor automatically created:

Name: "Wärmemenge" (DE) / "Heat Output" (EN)
Formula: Pellet Consumption (kg) × Energy Content (kWh/kg) × Efficiency (%)
Configurable Parameters:
- Pellet Energy Content: 3.0-6.0 kWh/kg (Default: 4.8)
- Boiler Efficiency: 50-100% (Default: 90%)
Example: 100 kg × 4.8 kWh/kg × 0.90 = 432 kWh
Compatible with HA Energy Dashboard
Tracks total heat output from pellet heating
Sensor attributes show current calculation parameters

Security Considerations

⚠️ Important:

Telnet is unencrypted and unauthenticated
Use only on trusted local networks
Consider VPN for remote access
Firewall appropriately

Development Status

Feature	Status
Telnet Client	✅ Complete
Message Parser	✅ Complete
Config Flow	✅ Complete
Coordinator	✅ Complete
Sensors	✅ Complete
Translations (EN/DE)	✅ Complete
Documentation	✅ Complete
Unit Tests	⚠️ Starter files
HACS Integration	⏳ Pending
HA Core Integration	⏳ Future

Future Enhancements

Write support (send commands to boiler)
Additional sensor platforms (binary_sensor, switch)
Historical data tracking
Efficiency calculations
Predictive maintenance alerts
Custom Lovelace cards
Comprehensive unit tests
Integration tests

Code Quality

✅ Type hints throughout
✅ Docstrings for all public functions
✅ Error handling at all layers
✅ Async/await (no blocking I/O)
✅ Thread-safe data access
✅ PEP 8 compliant
✅ Home Assistant conventions followed

Documentation

README.md - User-facing overview
INSTALLATION.md - Step-by-step setup guide
ARCHITECTURE.md - Technical deep-dive (20+ pages)
DEVELOPMENT.md - Developer workflow
CONTRIBUTING.md - Contribution guidelines
PROJECT_SUMMARY.md - This file

License

MIT License - See LICENSE file

Support & Contributing

Issues: Report bugs and request features
Discussions: Ask questions, share ideas
Pull Requests: Contribute code (see CONTRIBUTING.md)
Documentation: Help improve docs

Contact

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Last Updated: 2025-11-22

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Hargassner Pellet Boiler Integration - Project Summary

Overview

Key Features

Project Structure

Technical Architecture

Layer 1: Telnet Client (`src/telnet_client.py`)

Layer 2: Message Parser (`src/message_parser.py`)

Layer 3: Coordinator (`coordinator.py`)

Layer 4: Sensor Platform (`sensor.py`)

Layer 5: Configuration (`config_flow.py`)

Data Flow

Firmware Support

Example Telnet Message (V14_1HAR_q1)

Error Handling

Connection Errors

Parsing Errors

Update Errors

Performance

Installation

Via HACS

Manual

Configuration Example

Available Sensors (Standard Set - 27 Sensors)

Energy Dashboard Integration

Security Considerations

Development Status

Future Enhancements

Code Quality

Documentation

License

Support & Contributing

Contact

FilesExpand file tree

PROJECT_SUMMARY.md

Latest commit

History

PROJECT_SUMMARY.md

File metadata and controls

Hargassner Pellet Boiler Integration - Project Summary

Overview

Key Features

Project Structure

Technical Architecture

Layer 1: Telnet Client (src/telnet_client.py)

Layer 2: Message Parser (src/message_parser.py)

Layer 3: Coordinator (coordinator.py)

Layer 4: Sensor Platform (sensor.py)

Layer 5: Configuration (config_flow.py)

Data Flow

Firmware Support

Example Telnet Message (V14_1HAR_q1)

Error Handling

Connection Errors

Parsing Errors

Update Errors

Performance

Installation

Via HACS

Manual

Configuration Example

Available Sensors (Standard Set - 27 Sensors)

Energy Dashboard Integration

Security Considerations

Development Status

Future Enhancements

Code Quality

Documentation

License

Support & Contributing

Contact

Layer 1: Telnet Client (`src/telnet_client.py`)

Layer 2: Message Parser (`src/message_parser.py`)

Layer 3: Coordinator (`coordinator.py`)

Layer 4: Sensor Platform (`sensor.py`)

Layer 5: Configuration (`config_flow.py`)