How to Debug Smart Home Automations That Stop Working

Step 1: Check if the automation is enabled. Sounds obvious, but Home Assistant silently disables automations during certain update processes. Go to Settings > Automations and verify the toggle is on. Also check if someone (or another automation) disabled it via a service call.

Step 2: Verify the trigger device. Go to Developer Tools > States and find the entity that triggers your automation. Is it reporting data? Is it "unavailable"? A dead battery in a Zigbee sensor, a WiFi device that lost its connection, or a device that fell off the Zigbee mesh will show as unavailable. This is the most common cause of broken automations.

Step 3: Check the automation trace. Go to your automation, click the three dots menu, and select Traces. This shows exactly what happened the last time the automation triggered (or attempted to trigger). You can see which conditions passed or failed, which actions ran, and any errors. This is the single most useful debugging tool in HA.

Step 4: Check the logs. Settings > System > Logs. Filter for errors related to your automation or the devices involved. Common errors: "Entity not found" (device renamed or removed), "Service not found" (integration updated and changed the service call), "Timeout" (device did not respond in time).

Step 5: Test manually. Go to Developer Tools > Services and manually call the action your automation should perform. If the manual call works, the problem is in your trigger or conditions. If it fails, the problem is the device or integration itself.

Prevention is better: Set up a "device tracker" automation that alerts you when any device goes unavailable for more than 10 minutes. This catches problems before you notice broken automations. In HA, create an automation triggered by any entity state change to "unavailable" with a 10-minute delay condition. For more automation fundamentals, see our HA automations guide.