Offline does not always mean dead
A device can go unavailable because of power, range, routing, or integration issues without the hardware itself being bad.
Why your Home Assistant device is offline
This guide is for the moment when an entity that used to work suddenly disappears, stops reporting, or shows unavailable. The goal is to separate true device failure from power, radio, network, or integration-path trouble before the setup gets re-paired or rebuilt unnecessarily.
Recent changes matter
A moved sensor, coordinator change, Wi-Fi change, or update can explain the next best check.
Re-adding everything too early hides the cause
It is usually better to confirm the path that failed before wiping out the evidence.
Keep the diagnosis small
- Check whether only one device is offline or whether a group of devices failed together.
- Review power, batteries, and the device's recent physical location before deeper changes.
- Notice whether the issue followed a restart, update, automation edit, or radio-path change.
- Confirm whether the entity is unavailable in Home Assistant or whether the device itself is unreachable first.
Open the next page that matches what changed
Start with interference or pairing if the radio path changed. Start with the starter guide if the whole setup still feels shaky.
If the symptom stays active
Open the right live flow
Availability path
Pairing path
Automation path
Recommended next tools
Use the starter kit only after the failure path is clearer
This page should still lead with batteries, power, location, and radio-path checks before replacing anything. When the issue really points back to the starter hardware path, use the reusable kit page so those recommendations stay centralized.