With the old SmartThings website, you could go into the hub settings and change the Zigbee channel.
But now, since that site is gone, how do we change the Zigbee channel.
You donât now. And as @JDRoberts has suggested in several other topics, itâs unlikely it will come back because Zigbee and Thread share the same radio making it dangerous to allow a user to manually change the Zigbee channel and possibly stomp on the channel Thread is using.
So now that I have a wifi network interfering with my Zigbee channel 20, what do I do? I didnât have any Zigbee issues, with my second hub (v3), until someone starting using WiFi channel 9 yesterday. My first hub (v2), still on channel 25, has been fine.
Unfortunately you probably have to wait until they enable the functionality in the Advanced Web App. There seems to be code to do it, though to my eyes the GET and POST are the wrong way around. Iâm not subscribing to the theory that it wonât be possible.
I wouldnât say it was âdangerousâ I just think that itâs likely that whatever the customer did, the radio is going to change the channel again on its own in the new architecture, since it will be doing that for thread anyway. When the radio does this, we say that it is âfrequency agileâ and that is common in Zigbee platforms, although smartthings has not done it up until now.
My suggestion would be to get in touch with smartthings support and see what they say.
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They must have changed something recently. I now see the option to change the Zigbee channel on the SmartThings Hub website.
And that solved my issues. Soon after I changed my v3 hub to Zigbee channel 25, my offline devices showed back up again.
I had just received an Aeotec Hub today. I wanted to rule out any issue with my Samsung v3 hub. So now I guess I will have my v2 hub as a spare. Although I will run all three for a while to make sure I donât have any issues. And gradually move everything off my Samsung v2 Hub. And then off my Samsung v3 Hub. And hopefully I will be able to run all my 110+ devices off the Aeotec hub.
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Interesting. Iâll be curious to see if it stays changed if you are also using thread. 
The warning message is interesting:
âChanging the Zigbee channel may impact the Thread network channel if your hub supports Thread. In certain cases this channel change can impact Zigbee device connectivity of this hub or other hubs currently attached to the same Thread network.â
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If they use the same radio, by definition, the Zigbee channel is stomping on the Thread channel.
Not by definition. The chip is designed to gracefully swap between the two protocols if allowed to do so automatically. Itâs sort of like those old telephone switchboards where the operator would manually unplug from one line to connect another, but then swap back as needed. only the chip is doing it super quickly.
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Does the Thread stack and Zigbee stack have to run on the same channel?
Thatâs complicated.
Historically this kind of design has been âfrequency agile,â meaning the radio could and would change the channel on the fly if quality of service had declined due to local interference.
(Itâs also sometimes called âfrequency hoppingâ as in the FHSS protocol, but we usually try to avoid that when talking about a mesh network since âhopâ is already used in a different way.)
And it could also change channels when moving from one protocol to another.
All of that is allowed for in the independent third party specs for both Zigbee and thread.
BUTâthat kind of architecture requires that the end devices be able to keep up, usually by always listening on all channels. (Thatâs not the only way to do it, but itâs a popular way. Another way is for the hub to send out a message when itâs about to change the channel, but that can be an issue with sleepy devices. Yet another method is to have a pre-defined sequence of channels, and to move from one to the other as needed. That way the end devices know which channel to try next.)
Thatâs no problem for a single brand network, where all the devices are designed to work together with the same architecture. But it can be a huge issue for âpromiscuousâ networks like smartthings, which allow the use of many different brands with different engineering. In particular, a lot of the inexpensive brands will not be frequency agile.
Theoretically, if the end device canât reach the hub, it might be set to try a re-join on multiple channels, but if that fails, the device is lost to the network.
I havenât seen anything published anywhere on how smartthings is managing its new single radio Zigbee/Thread functionality with regard to channel changes.
So that leaves the following open questions until we do get some official answers
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Will the Thread network and Zigbee network be able to operate on different channels?
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will the thread network be frequency agile? (able to automatically change the thread channel if needed to overcome local interference)
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will the Zigbee network be frequency agile? (able to automatically change the zigbee channel if needed to overcome local interference)
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if either network is frequency agile, what happens to the other network if the channel is changed?
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if either network is frequency agile, does that network expect end devices to be listening on all channels? Or will it send out a channel update message at the time that it changes from one channel to another?
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if the customer manually changes the zigbee channel, what happens to the thread network?
Until we know the answers to those questions, we canât really predict what best practices will be for a stable platform.
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I donât think we really know. It wouldnât surprise me if that is one of the limitations of sharing Zigbee and Thread as SmartThings do.
It used to be the case that although Thread could change the channel number on the fly, the policy on when that would happen was made higher up the food chain. No doubt things could have evolved since then.
What I havenât really grasped is, if we consider Thread networks with multiple routers, whether SmartThings can change the channel and something else can change it back again. What happens then? Does the SmartThings Zigbee channel get changed to match?
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