Hi. Just unplug it. Give it a couple of days and it will disappear. The speaker is the room. 

Best to factory reset it before recycling.

I forgot to mention… you may be able to accelerate itisappearance by uninstalling the app and then reinstalling, making sure to choose to connect to existing system, not set up a new system.

The app just really gives you a view of what is in the system.  A speaker isn’t really in an app, it is just being viewed by the app. 

Thanks for your update and yes, speaker has disappeared from the "about my system" list but still appears on the "system settings" page.

Hopefully, in time it will disappear. 

Thanks!!

Just an update,  all disappeared after a couple of days so thanks for your valuable help!!

Why the hell is there no remove button?

i have replaced my Play:1 Satellites by Eras due to the Arc Ultra being incompatible (thx Sonos) and now I can’t remove the old ones? The only way to get rid of them is waiting a few days?

seriously, what programming logic is that?

Have you ever worked a support line?  I have, and I can tell you if you allow a customer to do something, a significant number will be doing it whether they want to or not.  The support calls for people who removed rooms temporarily, or by mistake, or were “just seeing what that button does” and now want them back would be untenable. 

Besides, what’s the big deal?  Are you that disturbed by waiting a few days?