# Open the web interface

> Find your Serin Controller on the local network, open its browser interface and locate everyday controls or settings.

Source: https://serin-labs.com/controller/web-interface.html
Last updated: 2026-10-27

The controller's web interface is available on your local network when its web server is enabled.

## Open the controller

1. Connect your phone or computer to the controller's local network.
2. Find its address. HomeKit-compatible firmware uses `http://Serin-XXXX.local`, with the controller's own four-character suffix. On Matter-compatible firmware, use the IP address from your router's connected-device list, because the `.local` address may not open. ESPHome uses `http://<device-name>.local`; after adding it to ESPHome, use the name you chose. The ESPHome dashboard also shows the IP address.
3. Open that address in a browser. If that address does not open, find the controller in your router's connected-device list and open `http://<controller-ip>`.

Use `http://`, not `https://`.

## Controls and settings

On HomeKit-compatible and Matter-compatible firmware, **Climate** changes mode and temperature; **Airflow** changes fan and vanes. See the [settings reference](https://serin-labs.com/controller/settings.html) for other sections.

[![Climate controls showing mode, target temperature and measured room temperature](https://serin-labs.com/assets/media/webui-climate.png)](https://serin-labs.com/assets/media/webui-climate.png)

Climate controls in the HomeKit-compatible web interface.

[![Closed section headings from Airflow to Diagnostics · Logs, including Modes, several with a status such as Connected, Paired, or the Wi-Fi signal in dBm](https://serin-labs.com/assets/content/860/media/webui-sections.png.465c7231be09.webp)](https://serin-labs.com/assets/media/webui-sections.png)

Web interface section headings. On Matter-compatible firmware the **HomeKit** section is named **Matter**. [View full-size screenshot](https://serin-labs.com/assets/media/webui-sections.png).

ESPHome's page shows configured entities and works while Home Assistant is unavailable. Keep **ESPHome web server** enabled when [customizing the configuration](https://serin-labs.com/controller/customize-esphome.html).

- [Change temperature, mode, fan and vanes](https://serin-labs.com/controller/everyday-use.html).
- [Set supported modes, vane type, names and units](https://serin-labs.com/controller/unit-settings.html).
- [Choose a room sensor](https://serin-labs.com/controller/room-sensors.html).
- [Update, back up or reset the controller](https://serin-labs.com/controller/manual.html#maintain).
- [Collect diagnostics and logs](https://serin-labs.com/controller/support-info.html).

[![Device settings with a name, temperature unit, vane type and Save Settings button](https://serin-labs.com/assets/content/860/media/webui-device.png.7776b7935aed.webp)](https://serin-labs.com/assets/media/webui-device.png)

[Device settings](https://serin-labs.com/controller/unit-settings.html) in the HomeKit-compatible web interface.

## Modes and temperature ranges

The **Modes** section controls availability and target limits for each mode. [Set modes and temperature ranges](https://serin-labs.com/controller/unit-settings.html#modes) for your indoor unit.

## Identify a controller

On HomeKit-compatible and Matter-compatible firmware, select **Firmware** > **Flash LED**. That controller's light blinks white for three seconds.

## If the interface does not open

If the IP address also fails, follow [Wi-Fi recovery](https://serin-labs.com/controller/wifi.html). A reachable controller with missing heat-pump data needs [CN105 troubleshooting](https://serin-labs.com/troubleshooting.html#cn105-no-data).