Where? In a new location, and different network? Or with a second account? Give us a few clues…

So can I have the Old and New Sonos system on the same Wi-Fi system playing separately or un synced as my wife might be watching a film in the Living Room whilst I might be watching Sport or playing a game in my Den upstairs in our house?

Living Room: S1

Sub

Playbar

Play 1 + Play 1 (stereo paired)

Den (Upstairs): S2

Sub 3rd Gen

Arc Soundbar

Era 100 + Era 100 (stereo paired)

? 

All speakers can play something different, or be grouped or ungrouped. You don’t need a separate ‘system’ to play different things on different speakers.  

Are your paired speakers (the Play 1s and the Era 100s) meant to be acting as surrounds? I’m assuming so. If that’s the case, then you’ve not set them up properly. The Play 1s should be bonded to the Playbar (by pressing Add Surrounds in the Playbar settings), not stereo paired. And the Era 100s should be bonded to the Arc (by pressing Add Surrounds in the Arc settings), not stereo paired. Unless you set them up like this, you’ll not get any 5.1 surround sound. 

Sorry if I am misunderstanding.

All your speakers are capable of running S2, should you want to get them into a single system ( though it might be best to wait a few weeks for the teething issues of the latest app version to iron out). 
 

You can then access them by room name, a simple labelling system Sonos uses. So you’ll have a room called “Living Room”, which can have the home theatre system built onto your Playbar with the Play:1’s bonded as surrounds (or the Play:1’s a stereo pair, not bonded as surrounds, and called “Living Room Music” to differentiate them from the Playbar. Then have another room called Den.
 

When you want to, you can group rooms so that they play the same source, or by selecting, say, Den you can stream your music to just that room. 
 

If you’ve not seen it, there’s also a tv Autoplay selector, so the tv source is auto selected when the tv is turned on. 

Thank you both for the excellent advice - I have ensured I had the latest version of the Sonos App and uninstalled the living room and reinstalled the Luving Room equipment and added the Play 1’s via the surround option and all good as it was before I got the new Den equipment.

now I’m going to try and install the Den equipment again on the latest version of the App and hopefully I will then have two separate home cinema systems.

What has gone so wrong with the Sonos Support Section - waited over 75 minutes with no connection on Friday and today they are stating a wait time of 140 minutes which is making want to return the new Arc equipment as that is just not acceptable and frankly ridiculous?

Thanks guys got it all working now have you considered taking over the Sonos Support Desk

Because I don’t always agree with people in their moaning, many people think I must already work for Sonos... 

With all going on with the latest app, I think I’ll pass thanks!

Well that didn’t last long now neither system is working ffs i surrender 

In what way? What are you seeing or not seeing in the app?

I have got the system back in the living room but I had to disconnect the sub in the living room to add the new sub in the Den and when I select add a second sub it only points to my new sub in the den???

All the systems are on in the den but no sound but everything is shown as connected in the Den within the app with volume around 50% and it’s not shown as muted???

Right I now have a fully operational old system in the Living Room but still no sound in the Den.