home-assistant/core · error · UpdateFailed

err

Error message

err

What it means

The atag coordinator wraps atagOne's AtagException into UpdateFailed inside _async_update_data, guarded by a 20-second async timeout. It signals any non-auth failure while the pyatag library talks to the Atag One HVAC controller (its local web API). If the 20s timeout trips instead, asyncio.TimeoutError propagates and the coordinator also treats the update as failed.

Source

Thrown at homeassistant/components/atag/coordinator.py:48

            config_entry=config_entry,
            name="Atag",
            update_interval=timedelta(seconds=60),
        )

        self.atag = AtagOne(
            session=async_get_clientsession(hass),
            **config_entry.data,
            device=config_entry.unique_id,
        )

    @override
    async def _async_update_data(self) -> None:
        """Update data via library."""
        async with timeout(20):
            try:
                await self.atag.update()
            except AtagException as err:
                raise UpdateFailed(err) from err

View on GitHub (pinned to 58a3fdb3ea)

Solutions

1. Confirm the Atag One is reachable: open its local web UI from the HA host (port 10000)
2. If the IP changed, use the reconfigure flow or reserve a static DHCP lease
3. Power-cycle the Atag One if its web API is wedged
4. If updates are consistently slow, ensure the 20s timeout is adequate (device responding at all)

try:
    await coordinator.async_config_entry_first_refresh()
except (ConfigEntryNotReady, UpdatesFailed):
    # AtagException wrapped in UpdateFailed; retry later, sensors hold last values
    raise

When it happens

Trigger: await self.atag.update() raising AtagException: device unreachable on the LAN, malformed/short HTTP reply from the controller, pairing status issues; or slow device exceeding timeout(20).

Common situations: Atag One thermostat lost Wi-Fi or got a new IP; device briefly offline (boiler maintenance); local API disabled by an firmware update; HA host network segmentation blocking port 10000.

Related errors

• Unable find multi-factor auth module: {mfa_module_id}
• current_conditions_update_error
• forecast_update_error
• Error communicating with API: {e}
• Got invalid status from device

AI-assisted analysis of home-assistant/core@58a3fdb3ea (2026-08-14). Data as JSON: /api/errors/9e2d7343cabd14f9. Report an issue: GitHub.