Hi @Delorean937.

Welcome, thank you for reaching out to Sonos Community since you already tried some troubleshooting steps let me try to assist you.

Can you try to factory data reset the arc and connect the ethernet cable from the arc to the router.

Once you're able to see the arc in the Sonos app. You need to set up the speaker wirelessly again Go to Settings » System » Network » Wireless Setup.

Let us know if it works. If you need help with any other information, please be sure to let us know.

@Delorean937 .  You already have a Sonos system?  You aren’t trying to do this as a system setup are you?  If you are simply adding the Arc to an existing system you should just go into System, Add Product.  Is that what you are doing?

i’ve been experiencing the same issue for a few days now. i have all of the latest devices from sonos. it’s driving me nuts to the point where i’m literally losing sleep over it. please, fix this issue immediately sonos!

I will try the Ethernet set up today but I think it’s a lot to go through to set up a speaker system since my router is in the ceiling.  I will report if it works or not. 

Ok so to report back after 5 times connecting it to my router and unplugging it and setting it back downstairs the system works for now. I got it all set up earlier today and then walked away for while and then I couldn’t find it in the app so I had to do it all over again. Now I’m having this message because my subwoofer won’t stay connected with WiFi. I tried resetting back to factory and reconnecting. No sound. The only way this works is with a Ethernet cable connected. This has got to be the most inconvenient set up process I have ever gone through.  

Hi @Delorean937.

Welcome, thank you for reaching back to Sonos Community.

While the ethernet cable is connected to the missing speaker, You need to set up the speaker wirelessly just go to Settings » System » Network » Wireless Setup.

Here are also the router settings that need to be verified. You can contact your ISP or the manufacturer of the router for assistance.

a. Auto channel must be set to Off

b. Choose best non-overlapping channel (1,6,11)

c. Set channel bandwidth to 20MHz

d. Both 2.4GHz and 5GHz should be enabled

e. 802.11 band should be set to b/g/n

f. Airtime Fairness should be disabled

Let us know if it works. If you need help with any other information, please be sure to let us know.

The subwoofer will only work with an Ethernet cable connected I followed all of your steps and nothing. I activate WiFi and then I loose the subwoofer all together never shows back up. What can I do next I mean I spent $600 on this subwoofer and would like to use it 

Update: So I am am still at square one. Arc is connected and no subwoofer connected. I have tried to set this subwoofer up wirelessly and with the Ethernet cable. No luck with WiFi. Can only be used with an Ethernet cable plugged in which is not even to the system. $300 systems don’t have this problem I know because I had one and wanted something nice for myself. Can someone from Sonos recommend what to do. I’m extremely upset that I have a $700 paperweight. Please assist 

I had a similar problem with a One SL. I have an Arc, Gen 3 Sub and two One SLs.

One of the One SLs refused to stay connected to the network. I called Sonos and went through all the troubleshooting steps, changing network parameters, direct connections. Nothing worked, I even bought a boost.

After 3 days and 7 hours worth of phone calls I demanded an RMA. On the 4th day they agreed and sent me a new One SL. This works perfectly. The WiFi module must have been defective.

If I were in your position I would give Sonos a call requesting an RMA.

That’s awesome thank you for the response. I’m wasting a lot to time after work trying to get this system to work and it’s very upsetting. I will give them a ring to see what I can do and I will report back. Thank you again 

What router are you using?
Does it have separate 2.4ghz/5ghz bands?

Any other WiFi access points?

Have you tried reserving the Sonos IP addresses in your DHCP reservation table - it sounds like a DHCP server issue to me (do you perhaps have more than one server on your local subnet?)

Any updates on this? I had the same issue before and unplugging/plugging the router used to work. Now It wont show on my app regardless of any method, including factory resetting and setting it up as a new device. 

This is not a coincidence. There is clearly something wrong here. The fact that I have this exact same issue, the fact that there are other people here talking about it with the exact same symptoms, and the fact that here I am AGAIN at this thread because I’m currently struggling with it for a 3rd time in a 3 month period.. literally the worst product experience I’ve had. I’m a software developer, so I’m not a dummy, but its literally as if Sonos won’t even acknowledge there may be an issue here. Maybe it has to do with an ISP, specific router, router configuration, band steering (I have At&t, anyone else?) - I’m not sure but there needs to be some action on Sonos’ part to figure this out and why different people are having the same strange issue.  

My Sonos system used to be my most loved piece of tech in my house, but not anymore. I was planning on getting 2 additional Arc’s soon, but seeing as this is happening to others with the Arc, I’ve decided not to. 

We literally have an entire home of Sonos products - 6 Play:1’s, 2 Playbars, 2 Subs, a Sonos Beam, 2 Sonos Ones, a Sonos Move, and a Sonos Bridge. I’ve been a loyal customer for years. With all these products you can only imagine the sheer frustration of having to factory reset them all repeatedly. This is now the third time in a matter of 3 months that I’m having this exact same issue. Literally the most frustrating thing in the world. After hours of attempting to fix it each time, it may randomly work and stay working for awhile…. until it doesn't.

For what its worth I’ve determined that no matter what you do, it doesn't matter. It is completely random. You have to continually factory reset all of your Sonos products, reset the app (or better yet delete it and re-download it), reset your wifi, literally the entire playbook of troubleshooting here, and only then will it RANDOMLY, just maybe, work. You’ll spend hours beating your head against the wall. You’ll be unable to pull the power cord out of your devices after having to do it so many times in a row.

If you do magically get it to work, it may work fine for a month or so, but then one day you’ll come home and its no longer able to find any of your Sonos products on your wifi. I’ve literally wasted 3 days of my time on this same issue and it keeps happening.

I used to be the biggest advocate for Sonos. I’ve sent them soooo many customers. But a year or two ago I started having random weird issues with my products with no explanation other than to keep trying to reset them. It sucks. When it works, it's great. But now with this issue repeatedly occurring I’m throwing in the towel. Unfortunately after wasting so many hours on trying to fix this crap, I’ll be switching to a new speaker company soon and will no longer be recommending Sonos to anyone. So disappointing.

Since you are not telling us anything about your wifi set up, helping you is not possible.