Home Assistant Automation Runs Twice: Quick Trigger Checklist

Direct answer: If a Home Assistant automation runs twice, do not assume Home Assistant is randomly duplicating it. The usual causes are two triggers responding to the same event, a state trigger reacting to attribute changes, or a time trigger landing in a repeated clock hour. Start with the automation trace and identify the trigger that created each run before changing the automation. For the full step-by-step diagnosis, see the complete trace-based guide.

What “runs twice” actually means

First separate two different symptoms. If you see two traces starting almost together, the automation may have been triggered twice. If you see one run but an action happens twice, inspect the action itself, scripts it calls, or another automation that controls the same device. Those are different problems and need different fixes.

1. Check the traces before editing anything

Open Settings → Automations & scenes and select the automation.
Open Traces and compare the two runs.
Look at the trigger information and timestamps.
Write down the entity, event, time trigger, or other trigger that started each run.

Home Assistant’s current troubleshooting documentation recommends using traces to determine why an automation ran. Preserve that evidence before changing the trigger configuration.

2. Look for two triggers responding to one change

An automation can contain multiple triggers. Two of them may legitimately react to the same real-world change. For example, a device event can be accompanied by a state change, or two closely related event sources can both call the same automation.

Compare the trigger that fired in each trace. If both traces point to different triggers, decide whether both are actually required. If only one trigger should start the workflow, remove the redundant trigger rather than adding delays or helpers to hide the duplicate.

3. Check whether a state trigger is also reacting to attributes

A state trigger can react when an entity’s attributes change, not only when its main state changes. A light may keep the same on state while brightness changes; a sensor can keep the same state while an attribute updates.

If the automation should respond only to a particular state transition, make the trigger explicit with the appropriate From and/or To state. Home Assistant documents this as a common reason an automation appears to run more often than the visible state changes.

4. Check time triggers and daylight-saving transitions

If the duplicate happens at a clock time rather than immediately after a device change, check the time trigger. Home Assistant documents a special case when clocks move backward: a time that occurs during the repeated hour can occur twice that day.

That is different from a permanently duplicated automation. If the behavior happens only on the daylight-saving transition, do not rewrite the automation simply to compensate for one repeated clock hour. Choose a time outside the affected hour when the job must occur exactly once.

5. Check whether another automation or script is doing the same job

Sometimes the automation is not actually running twice. A second automation, script, blueprint, device routine, or manufacturer cloud rule may control the same light, switch, scene, or notification.

Search for other automations and scripts that reference the affected entity. Then test the target action with the smallest safe change. A duplicated notification is especially useful evidence: if the automation has one trace but the notification appears twice, the duplication may be downstream.

6. Do not use the automation mode as the first “fix”

Automation mode controls what happens when a new run starts while an existing run is still active. It does not, by itself, identify why two triggers occurred.

Single: a new run is not started while one is already running.
Restart: a new run stops the previous run and starts again.
Queued: new runs wait for earlier runs, subject to the configured limit.
Parallel: multiple runs can execute at the same time, subject to the configured limit.

If your traces show two genuine triggers, changing the mode can change the symptom without removing the cause. Diagnose the trigger first.

A safe diagnostic sequence

Reproduce the duplicate once.
Compare the two traces and record their trigger IDs or trigger descriptions.
Identify whether the triggers are different or the same.
If they are different, inspect whether both are necessary.
If the trigger is a state trigger, check whether attribute changes are involved.
If it is time-based, check the time zone and whether the duplicate matches a daylight-saving transition.
Search for another automation, script, blueprint or device routine acting on the same target.
Make one small change only.
Reproduce the original condition and confirm the trace count and final device behavior.

How to verify the fix

Do not stop after seeing one successful run. Recreate the original trigger at least twice under normal conditions. Confirm that the expected automation trace appears once, the intended action happens once, and the target entity reaches the expected state.

If the original problem was intermittent, leave the configuration unchanged long enough to cover the interval in which the duplicate normally appeared. Remove temporary test helpers or extra logging after the diagnosis.

When the problem is not an automation duplicate

If Home Assistant shows one trace but a device changes twice, look downstream. Check scripts called by the automation, scenes, other automations, device-side routines, and integrations that can independently issue commands. If the trace itself shows two starts, stay focused on triggers and timing first.

Frequently asked questions

Can a state trigger run twice without the device visibly turning on and off?

Yes. Attribute changes can cause a state trigger to fire even when the displayed state remains the same, depending on how the trigger is configured.

Should I change Single to Parallel?

Not just because an automation appears to run twice. Mode changes affect concurrency; they do not explain the original trigger. Identify the duplicate trigger first.

Why would a time automation run twice only once a year?

A daylight-saving clock change can repeat an hour. Home Assistant documents that a time trigger scheduled during the repeated hour can therefore occur twice on that day.

What is the fastest evidence to collect?

Capture the two trace timestamps, the trigger that started each run, and the target entity or action that duplicated. That usually separates trigger duplication from downstream duplication quickly.

Sources and testing note

This guide was checked against Home Assistant’s current automation troubleshooting documentation on October 3, 2026. It is a documentation-based troubleshooting guide, not a report of hands-on testing on a particular Home Assistant installation.