Hi tedgotsoul, welcome to the forum.
Scenes are a one shot deal - they set things to a certain state and then stop, so it’s not possible to do what you want using just a scene.
Here’s one way you could achieve it (assuming your away temp is 15 and home temp is 21, just for example sake)
Have a scene that sets ‘Away’. It has the following actions:
- Set thermostat temp to 15
- Set location mode to Away
Next, create a custom automation:
- Condition: If home mode is set to away
- Action: Set thermostat temp to 21 with a delay of X hours
This way, by running the scene you’ll trigger an automation immediately, but it won’t actually perform the action until X amount of time has passed.
This has a limitation that you won’t be able to cancel the automation action. But it should work as you describe.
On a side note, this is the sort of thing that annoys me a bit about SmartThings. Scenes are effectively just automations that get triggered manually, but there are also certain things you can’t do with scenes (such as the delay described above.) I think SmartThings should drop ‘Scenes’ entirely as a separate entity, and allow you to set a ‘trigger’ called ‘manual’ - which causes an automation to appear in the UI as a scene does. It simplifies things a lot, but also gives you more flexibility and control.