Even several years after its announcement, using a Google Home speaker, or any other device with Assistant, feels a little like participating in a special beta test. Things seem really simple, until they're not. Delve a little beneath the surface and there's a smorgasbord of nuances and quirks, like native smart home integrations versus Actions on Google, or voice-dependent actions versus ones available for all guests, that aren't easy to wrap your head around unless you're as involved with the ecosystem as possible.
But one misstep leaves many of us puzzled. Once a Google Home, Assistant speaker, Nest Hub, or other Smart Display is linked to your Google account, you may not be able to remove it unless you're on the same Wi-Fi network. There is a method, but even Google's support documents and multiple support threads asking about this don't mention it.
When you're away from the Wi-Fi network the smart speaker or display is set up on, you may or may not be able to access its settings. Open the Google Home app, tap any Assistant speaker or display you've linked, and you'll see one of two interfaces — I'm not sure why there are two. In one of them, the settings button is gone (middle screenshot), and in another it's still there (right screenshot) but may not work properly all the time.
Left: When on the same Wi-Fi network. Middle & Right: When away, you get one of these.
If you can access the settings button, good for you. If not, you'll have to go through another, longer route.
Go to the bottom right tab in the Google Home app (the one with a profile icon), choose Settings, then move to the second tab for Assistant. Scroll down and you'll find all Assistant devices linked to your Google account, even those you don't have access to right now via Wi-Fi. Tap the one you want to remove and you'll get the same page as if you had tapped the missing settings icon I mentioned earlier.
Left: Profile tab in Home app, choose Settings. Middle: Go to Assistant tab. Right: Scroll down to get Assistant devices.
Once you're in the device's settings, regardless of how you got there, you can scroll down to find all the options you want. Disable Personal results if you don't want your calendar, photos, emails, to be accessible from that device. Disable Notifications to stop reminders from showing up there. You can also remove Voice Match to stop the device from recognizing your voice. But most importantly, you can completely remove the device from your account. Again, this works even when you don't have physical access to the device or Wi-Fi network it's connected to.
Left: Google Home settings. Middle: Unlink Voice Match. Right: Remove the device completely.
And that's all you need to know.
The Google support documents don't explain this fully. I found one doc for removing Voice Match and another for turning personal results off, but nothing about completely unlinking a device or what to do when that settings button doesn't show up.
We started looking into this issue when a reader, Susanna, tipped us about it. She had bought a Google Nest Hub (né Home Hub) for her parents while visiting them in the UK, set it up for them, then traveled back home to the US. She later discovered that her photos were showing up on her parents' display, and so were her reminders. Her account was obviously still linked to it, but looking into the Google Home app, she couldn't remove the device from her account because she wasn't on the same Wi-Fi network and the settings icon wasn't showing up. After dozens of chats, emails, and calls with Google support, the only solution was to walk her elderly parents through resetting the device and linking it again with their account — well that or travel back to the UK.
Imagine if the device was set up for a disabled or tech-averse person who can't reset it. Or if you've left an abusive/difficult partner and you couldn't unlink your account from a device in their house unless you traveled back there. Or if you've sold your speaker or display to someone and forgot to unlink your account beforehand. Imagine if all your broadcasted messages, reminders, photos, and personal info were being shared on that speaker and you couldn't stop it unless you had physical access to it.
I'm hoping a proper support document is created for this so that it's easier for everyone to get their answer, but in the meantime, this guide should do the trick.