This guide explains how to pair and manage your existing eQ-3 MAX! heating system devices (thermostats, window contacts, etc.) within Home Assistant using the custom ESP32-C6 Matter Bridge.
If you haven't flashed your ESP32-C6 yet, you can use the pre-compiled factory binary found in the binaries/ folder of this repository.
Run the following command (adjust the COM port ttyACM0 or /dev/serial/by-id/... to your system):
esptool.py --chip esp32c6 -b 460800 --before default_reset --after hard_reset write_flash --flash_mode dio --flash_freq 80m --flash_size 4MB 0x0 binaries/max_matter_bridge_factory.binThe firmware uses the standard Matter BLE (Bluetooth Low Energy) commissioning process.
- Power on the ESP32-C6 Bridge. It will automatically start broadcasting via Bluetooth.
- Open the Home Assistant Companion App on your smartphone.
- Navigate to Settings -> Devices & Services.
- Tap Add Integration (bottom right) -> Add Matter device.
- Choose "Setup without QR Code" and enter the standard test pairing code:
34970112332 - In the Bluetooth device list that appears, look for a device named
MAX-XXXX(where XXXX are the last characters of your bridge's MAC address, e.g.,MAX-9E5C). Select it. - Home Assistant will connect via Bluetooth and securely transmit your Wi-Fi credentials to the Bridge.
- Once added, assign the "MAX! Bridge XXXX" to a room.
Instead of manually typing 24-bit RF addresses, the bridge features a Virtual Auto-Discovery Switch.
- Look at the newly added Bridge device in Home Assistant. You will notice it exposes a Switch entity (often named
MAX-DISCOVERY). - Enable Pairing Mode: Toggle this switch to ON. The bridge is now in "Sniffing/Pairing" mode.
- Wake up your MAX! Devices: Go to your physical MAX! Thermostats or Window Contacts and force them to transmit a packet:
- Thermostat: Turn the dial to change the temperature.
- Window Contact: Open or close the window.
- Wall Thermostat / Push Button: Press a button.
- Automatic Registration: The bridge instantly intercepts the packet, extracts the unique address (e.g.,
0x01CAC5), saves it to its internal memory (NVS), and dynamically creates a new Matter endpoint. - A new Thermostat or Contact Sensor will automatically appear in Home Assistant, grouped under your Bridge!
CRITICAL: Once you have paired all your local MAX! devices, turn the Auto-Discovery switch OFF. Leaving it on may cause the bridge to accidentally sniff and register your neighbor's MAX! devices.
According to the official Matter Specification, the "Auto" mode is strictly for HVAC systems that can both heat and cool. Since MAX! thermostats are heating-only, the Matter standard mandates that the "Auto" mode is hidden.
The bridge maps the modes as follows:
- Heat: Maps to MAX! "Manual" mode or "Auto" mode.
- Off: Maps to MAX! "Off" mode (typically 4.5°C).
Recommendation: It is highly recommended to control schedules entirely through Home Assistant (using Automations or Scheduler integrations) rather than relying on the physical MAX! device's internal weekly schedules.
Because the bridge must adhere to the 1% Duty Cycle (ETSI 868MHz regulation), you must be careful with aggressive automations.
- The Limit: The bridge can physically send roughly 30 to 40 commands per hour. (Receiving states from window contacts is unlimited).
- Best Practices: Do not create automations that change the temperature every few minutes. If you have 10 thermostats, avoid changing the temperature on all of them at the exact same millisecond; stagger the commands by a few seconds if possible.
- If you exceed the duty cycle, the bridge will log a warning and silently drop transmission commands until the internal "token bucket" has refilled.