# Serin Controller status lights and buttons

> Look up controller LED colors, blink patterns, NanoC6 Wi-Fi indication, and button hold actions by firmware.

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

[![NanoC6 with its turquoise button on top and three indicator windows below the USB-C port.](https://serin-labs.com/assets/content/800/diagrams/nanoc6-status-lights.webp.d6d363a1c799.webp)](https://serin-labs.com/assets/diagrams/nanoc6-status-lights.webp)

**NanoC6 button and indicators**  ButtonTurquoise surface on top. Indicator windowsThree openings below USB-C. RGB status LEDSee colors and patterns below. Blue Wi-Fi LEDOn when disconnected from Wi-Fi; off when connected. The NanoC6 RGB LED does not signal Wi-Fi loss.  LED meanings apply to HomeKit-compatible and Matter-compatible firmware. [Enlarge illustration](https://serin-labs.com/assets/diagrams/nanoc6-status-lights.webp).

## Status light meanings

For HomeKit-compatible and Matter-compatible firmware:

With ESPHome firmware, the LED is a standard Home Assistant `light` entity. The status meanings below do not apply.

| Light | What it means |
| --- | --- |
| Off | The controller is operating normally. |
| White solid | Starting up; normally turns off when the web interface is available, after about five seconds. · A new Matter-compatible controller stays white until added to an app. |
| White slow pulse | A firmware update is in progress. Do not disconnect power. If the update does not finish, see · [OTA update fails or the controller does not respond](https://serin-labs.com/troubleshooting.html#ota-recovery) · . |
| White fast blink | The identification function is active. The light turns off after three seconds. |
| Blue slow pulse | The setup Wi-Fi network is waiting for a connection. · On Matter-compatible firmware this is a recovery network; initial pairing uses Bluetooth. |
| Blue fast blink | The controller is connecting with the Wi-Fi credentials you entered. This may take up to 30 seconds. |
| Blue solid | Reconnecting after Wi-Fi loss, on boards without a separate blue Wi-Fi LED. See · [Wi-Fi troubleshooting](https://serin-labs.com/troubleshooting.html#wifi-drops) · . |
| Green solid | Confirmation: the controller connected to Wi-Fi or paired with a Serin Link. The light remains on for a few seconds. |
| Red solid | No response over CN105. See · [CN105 troubleshooting](https://serin-labs.com/troubleshooting.html#cn105-no-data) · . |
| Red fast blink, then stops | The most recent action failed. The Wi-Fi credentials may be incorrect, or Serin Link pairing was unsuccessful. |
| Red fast blink, continuous | The indoor unit is reporting an error code. The web interface displays the code. |
| Yellow slow pulse | Safe mode after repeated crashes. See · [safe-mode recovery](https://serin-labs.com/troubleshooting.html#safe-mode-light) · . |
| Purple slow pulse | A Serin Link pairing window is open. |
| Orange fast blink | The paired Serin Link was removed. The light blinks for two seconds, then the controller restarts. |
| Cyan slow pulse | The controller is on your network and has not been added to an app (Matter-compatible firmware). |
| Cyan fast blink | A pairing process is in progress (Matter-compatible firmware). |

Setup signals take priority over faults. Holding the board button overrides the current signal.

## Button hold actions

These actions apply to HomeKit-compatible and Matter-compatible firmware. See [Change Wi-Fi](https://serin-labs.com/controller/wifi.html) or [Restart and reset](https://serin-labs.com/controller/reset.html) for the full procedures.

Pairing actions happen on release. The Wi-Fi reset happens during the hold, at 10 seconds.

| Hold time | Light | Action |
| --- | --- | --- |
| 2 to 7 seconds | Purple solid | Release to open a Serin Link pairing window or remove the current pairing. Releasing while a pairing window is open cancels it. |
| 7 to 10 seconds | Red fast blink | No action. Release the button during this interval to cancel. |
| 10 seconds | Red fast blink | Erases the stored Wi-Fi credentials and restarts immediately, while the button is still pressed. |

On boards with a button but no RGB LED, the same press durations apply, but no visual indicator is available.