Cannot add STH-ETH-250 to SmartThings app

Devices & Integrations
1

I got a second hand STH-ETH-250. Based on the below, I factory reset the device. I believe it worked because I get a solid green led, however I cannot add the device to my app with the Welcome Code on the device. My serial number is 3010039808, is this still connected to the old account? Do I need a new Welcome Code?

Thanks!

2

Do you see any error codes in the app when you are not able to add it?

It is possible the welcome code is valid but the security certificate on the hub has expired. If the hub has not been active since March 2025… then that is most likely the issue. The error code may profile a clue. If that is the case, following the guide in the following thread: Troubleshooting SmartThings Hub 2018 and Aeotec Hub

LOL and the most obvious that I forgot. If the hub is still claimed on someone’s account, you would need to reset it first and then try adding it.

to reset:

Disconnect power cable from hub and remove any batteries.

Connect an Ethernet cable between hub and your network.

Press the reset slot and while continuing to press, insert the power cable.

Wait about 30 seconds until you see a solid yellow led on the front of the hub. Then release pressing the reset slot.

Try adding hub to app.

If that fails, following the troubleshooting linked above.

3

Thanks for your reply! Yes, I image the hub is/was claimed on someone else’s account since I got it second hand. Currently the LED is solid green which appears to mean it has a connection. I did try the reset procedure. I didn’t see any error codes in the app when I tried to claim it, I’ll try to do the reset again and if that doesn’t work the NTP blocking etc.

4

Okay I got it claimed, thanks!

This comment was particularly helpful: Troubleshooting SmartThings Hub 2018 and Aeotec Hub - #68 by JohnRichard

I also have and Asus so I used those ntp blocking instructions.

AND I missed a detail in the factory reset described in that comment as well:
Wait until the LED yellow flicker becomes solid (at ~30 seconds), then release the RESET button.

Finally, it seems like this STH-ETH-250 didn’t follow the LED Function Description described here: Troubleshooting SmartThings Hub 2018 and Aeotec Hub - #66 by JohnRichard

Instead of Red|Green it was doing a slower rotation of Red|Blue|Green and I claimed it in that window.

Thanks for all the great comments, details, and help in the forum I’d have never figured this out otherwise!

icw