If there is one Sonos Amp, and two ‘rooms’ connected to that single Amp, and one room isn’t working, you have a wiring issue, not a Sonos issue. 

Okay, thank you…why would it suddenly not be working? How do I problem solve/fix? The amp is in a closet that no one has access to or interacts with, so I’m not sure what had caused the problem. 

No idea, honestly. The first thing I’d check would be the wires on the back of the Amp, but the Amp isn’t smart enough to know (or separate) that two sets of speakers are wired to a single pair of speaker posts. 

I’d be talking to the person who installed these speakers, if nothing comes of checking the speaker posts on the back of the Amp. It’s possible that there is a disconnect somewhere along the wiring.

If there is no obvious wire issue you can do a basic test of the wires and speakers using a flashlight battery. Pull all the wires of the Amp, mark where each came from.

Pick one speaker's pair and touch them to opposite ends of the battery, the speaker should make a click sound. Tapping the wires multiple sounds will help locate the connected speaker.

If you find one that doesn't click you can pull it from the mount and check the wire connections there. You can use jumper wires and your battery to check the speaker directly too.

Thanks for the help. Could it be any issue in the app? Someone suggested making sure I had both rooms in the same zone, but I don’t see where/how to do that in the app. 

The app should show the zone, Sonos calls a Room for each of your Sonos devices, so each Amp will be listed individually. The Amp only streams a single source to the speaker terminals so only one zone / Room per Amp is possible.

The App only controls the Amp and has no possible way to even know how many speakers you have connected to it, much less control them.

You have a wire or speaker problem that needs diagnosed and fixed.

Okay, thank you! 

Okay, just had wire guy out…the wire has gone bad. Not sure how to re-run without tearing into walls. He mentioned swapping out for Sonos wireless in ceiling speakers. What are thoughts on this? Can I keep the two wired speakers into the room that is working and just replace the other two as wireless? Or, should I replace all four with wireless? Do these wireless and ceiling speakers work well? Or at least well enough to make it worth not tearing into walls again?

There are no wireless SONOS in-wall or in-ceiling speakers. Even if there were, you would need to bring power to the speakers or constantly replace or recharge the batteries.

Are there any speaker Volume controls?

I think he might be meaning the Sonance In-ceiling/in-wall architectural speakers but doesn’t realise they are just the speaker.

https://www.sonos.com/en-gb/shop/architectural

Given the silly price of them, it wouldn’t be unreasonable for someone who doesn’t know to expect speakers often titled as “Sonos In-Ceiling Speaker by Sonance” by retailers to assume they are self contained Sonos speakers, rather than speakers that need connecting to a Sonos Amp.

Sonos title them slightly differently in their store, “In-Ceiling Speakers by Sonos and Sonance” but until reading into the details at £700 (6”) or £1K (8”) a pair it isn’t clear they are just the speaker.

The main difference with them over other speakers is you can TruePlay them and a Sonos Amp officially supports up to 6 Sonance speakers, rather than only 4 8ohm speakers from other brands.

@buzz while active ceiling speakers aren’t as common as passive ones, they are available and can usually be powered from the lighting circuit or mains spur. Lithe Audio for example make some active wifi ceiling speakers with built in wifi, bluetooth, airplay, chromecast, spotify and line in. The Pro versions can be upgraded with a Wisa module and used with a Wisa decoder and transmitter to build a wireless audio 8 channel home theatre system 

Thank you both for your responses…I’m not really sure what to do now. I was a bit fooled by the wiring guy and what I saw on the Sonos website. I thought I had found a solution because the wiring guy says there is power for the speakers to connect to and then they can be linked to the amp through Bluetooth or WiFi? Obviously this is outside of my area of expertise. It sounds like my only real option is to find someone to re-run the wires, which is very discouraging as we’ve just finally finished our home building project and I hate to pull cabinets out and tear through walls now. If anyone has any other ideas please share them. Thank you all again for your help.