idm-heatpump-api 0.3.0

Python library for communicating with IDM Navigator heat pumps via Modbus TCP. Used by the official Home Assistant integration.

IDM Heatpump API

An asynchronous Python library for communicating with IDM Navigator heat pumps (2.0, Pro, and Navigator 10) over Modbus TCP.

This library is primarily designed to power the official IDM Heatpump Home Assistant Integration, but it can be used independently for any Python project that needs to monitor or control an IDM heat pump.

Documentation:

• GitHub Pages: https://xerolux.github.io/idm-heatpump-api/
• GitHub Wiki: https://github.com/Xerolux/idm-heatpump-api/wiki
• PyPI: https://pypi.org/project/idm-heatpump-api/

The docs/ directory is the single source of truth and is used for both GitHub Pages and Wiki sync.

Features

• Asynchronous: Fully async operations using pymodbus with automatic reconnection.
• Auto-Detection: Probes registers to detect the controller model, active heating circuits, zone modules, solar, ISC, PV, and cascade.
• Comprehensive Register Map: 100+ registers covering temperatures, energy, status, heating circuits (A-G), zone modules, solar, ISC, cascade, boosters, and more.
• Batch Reads: Intelligent grouping and batching of register reads for maximum efficiency.
• Resilient: Configurable retries with exponential backoff and permanent failure tracking for unavailable registers.
• Write Support: Safe register writes with validation, min/max bounds, and EEPROM-sensitive write protection.
• Metadata: Each register includes binary, state_class, icon, enabled_by_default, write_only, and exclude_from_write metadata for direct Home Assistant entity mapping.

Supported Devices

Device	Firmware	Heating Circuits	Zone Modules	Status
IDM Navigator 10	NAV10_20.23+ (2025)	up to 7 (A-G)	up to 10 (6 rooms each)	Confirmed
IDM Navigator 2.0	all versions	up to 7 (A-G)	no	Confirmed
IDM Navigator Pro	all versions	up to 7 (A-G)	up to 10 (6 rooms each)	Confirmed

Requirements

• Modbus TCP must be enabled on the IDM controller (Settings -> Building Management -> Modbus TCP = On).
• Default port: 502
• Default slave ID: 1
• Python 3.12+

Installation

pip install idm-heatpump-api

Basic Usage

import asyncio
from idm_heatpump import IdmModbusClient, build_register_map

async def main():
    client = IdmModbusClient(host="192.168.1.100", port=502, slave_id=1)

    try:
        await client.connect()

        # Auto-detect model and capabilities
        model_info = await client.detect_model()
        print(f"Detected: {model_info.model_name}")
        print(f"Circuits: {model_info.active_heating_circuits}")
        print(f"Solar: {model_info.has_solar}, ISC: {model_info.has_isc}")

        # Build register map based on detected model
        registers = build_register_map(model_info=model_info)

        # Read all registers in efficient batches
        values = await client.read_batch(list(registers.values()))

        for name, value in sorted(values.items()):
            reg = registers[name]
            unit = f" {reg.unit}" if reg.unit else ""
            print(f"  {name}: {value}{unit}")

        # Write a register (e.g. set DHW target temperature)
        if "dhw_setpoint" in registers:
            await client.write_register(registers["dhw_setpoint"], 48)

    finally:
        await client.disconnect()

if __name__ == "__main__":
    asyncio.run(main())

Advanced Usage

The library provides fine-grained control for advanced scenarios:

• build_register_map(circuits=["A", "B"], zone_modules=2, rooms_per_zone=4): Manual register map without auto-detection.
• get_heating_circuit_registers("A"): Registers for a single heating circuit.
• get_zone_module_registers(zone_index=1, room_count=6): Registers for a single zone module.
• client.probe_register(address=1850, count=2): Probe a single register without affecting failure tracking.
• client.reset_failed_registers(): Retry permanently failed registers.

Register metadata for HA integration mapping:

reg = registers["compressor_status_1"]
print(reg.binary)                # True -> BinarySensor
print(reg.writable)              # False
print(reg.write_only)            # False
print(reg.enabled_by_default)    # True
print(reg.state_class)           # None (or "measurement", "total_increasing")
print(reg.icon)                  # None (or "mdi:thermometer")
print(reg.exclude_from_write)    # None (or {255})

Navigator 10 Support

The library fully covers the official 2025 Navigator 10 Modbus TCP specification, including:

• Heat sink / plate heat exchanger sensors (flow rate in l/min at 1072)
• Power limitation registers (4108 / 4112) for demand response / peak shaving
• Complete Booster A + B (second heat generator) monitoring
• Additional source pump faults and external pump demand control
• Groundwater temperatures and more cascade bivalence points
• All zone module rooms (6 rooms per module on current hardware)
• PV / energy management, solar thermal, and ISC (Intelligent Surface Cooling)
• Cascade temperatures and bivalence points

Contributing

Please open an issue or pull request for bug reports, improvements, and documentation updates.

License

MIT License — see LICENSE.

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Support

This library is developed in my spare time. If you find it useful, consider supporting:

• Star the repository on GitHub
• Report bugs
• Share with other IDM heat pump owners

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Disclaimer

This project is an unofficial community project and is not affiliated with, endorsed by, or connected to IDM Energiesysteme GmbH.

All trademarks, logos, and product names (e.g., "IDM", "Navigator") are property of their respective owners. The logos and images used are solely for identifying the compatible device and are not used commercially.

This project is provided without any warranty. Use at your own risk — especially when writing Modbus registers.

IDM Energiesysteme GmbH has neither authorized nor endorsed this project.