Sonos gives two separate procedures for the Sonos Era 100: a restart in its reboot article and a factory reset in its factory reset article. The factory reset uses the power cord and the Bluetooth button on the back.

What This Problem Means

A restart powers the Era 100 off and on again. A factory reset goes further: Sonos says it removes “registration information, content saved to My Sonos, and content services”, and you then add the speaker to your Sonos system again. Sonos is clear it isn’t a first step: “We do not recommend resetting your Sonos product as a troubleshooting step.” The fix where Sonos does call for one is setup: if the app can’t find the speaker and its light isn’t flashing green, reset it and try again.

Common Symptoms

• The Era 100 has stopped responding and needs a restart
• The app can’t find it during setup and the light isn’t flashing green
• It was set up on another Sonos system before
• The light flashes orange and white, which Sonos says means updating or resetting

Safe Checks You Can Try

1. Restart first

Unplug the power cord, wait 10 seconds, plug it back in and allow one minute for the Era 100 to start up. That’s the method in Sonos’s reboot article. Then try whatever wasn’t working again.

2. Check whether you need a reset

Sonos’s product not found during setup article says to factory reset the speaker if it isn’t flashing green when you try to set it up. That can happen if it was set up on another Sonos system before. For other lights, Sonos’s LED lights article says to restart, not reset: solid orange means setup didn’t finish (or the speaker is overheating), and flashing red means a new or reset product wasn’t “set up within 30 minutes of powering on”.

3. Know what a reset removes

Sonos says a factory reset removes “registration information, content saved to My Sonos, and content services”. Afterwards, Sonos says to add the product to your system again, as you would a new speaker.

4. Factory reset the Era 100

Unplug the power cord. Press and hold the Bluetooth button on the back, and keep holding it while you plug the power cord back in. Keep holding until the front light flashes orange and white. Sonos says “the light will flash green when the process is complete.”

5. Add it to your system again

With the light flashing green, open the Sonos app, go to Settings > Add Speaker or Component and follow the prompts. Sonos’s article on adding a product to an existing system covers this. Keep your phone within 10 feet (about 3 m) of the speaker, as Sonos’s setup troubleshooting suggests.

6. If the light flashes red afterwards

Sonos says flashing red means a new or reset product wasn’t set up within 30 minutes of powering on, so restart it and set it up. Flashing red and white means “update failed”: restart it and try the update again from Settings > General Settings > System Updates > Check for Updates (Sonos’s update article).

When To Contact Support

If the reset doesn’t finish, or the Era 100 still won’t set up afterwards, contact Sonos and say which steps you’ve already tried. The Sonos Era 100 support page lists Sonos’s help articles for this speaker, and Sonos’s UK contact page has its phone and live chat options.

Last resort: factory reset. Use step 4 only after a restart hasn’t helped. For the Era 100, hold the Bluetooth button on the back while you plug it in until the light flashes orange and white, then wait for flashing green. Sonos says it removes registration information, content saved to My Sonos and content services, so you set the speaker up again in the Sonos app.