This.
The SmartThings hub is a very inexpensive device. Its Zigbee coordinator is pretty limited compared to more expensive devices. As @Mr_Lucky said, it cannot change its Zigbee frequency, either on the fly or as a user request. Whatever it was set to at the factory is what you’re stuck with. So, to be honest, “best practices” from a network engineering standpoint just don’t apply to a device of this type.
The best things you can do with a SmartThings hub to limit Wi-Fi interference:
A) put your smartthings hub at least 3 m from your Wi-Fi router. Also keep it away from metal.
B) whenever possible, put your Wi-Fi traffic on 5 GHz, not 2.4. And choose a 2.4 Wi-Fi channel which is the maximum distance from whatever Zigbee channel your SmartThings hub happens to be on.
C) don’t use boosted Wi-Fi in the 2.4 range
D) if you’re in the US, use boosted Zigbee devices when available. Most Zigbee home automation devices made in the US are boosted for exactly this reason. Also, replace batteries when they hit 50% instead of the more typical 20% to keep signal strength high.
E) if you can afford it, try to make sure that every battery operated Zigbee device has at least two mains-powered zigbee devices (but not Sengled, they don’t repeat) within range so that there’s always an option in routing. Zigbee light switches, in wall relays, and pocket sockets are good for this purpose. Remember that you are working with 360° signals, but signal doesn’t spread until it’s about eight or 10 feet from the device. So your best repeater might be a device one floor up or one floor below. But It can actually work better if the repeating device is also about eight or 10 feet left or right of where the other device is.
F) you can try alternative placements. As I’ve mentioned before, we have a Wi-Fi booster and if I put it on one wall in a room it kills all the ST Zigbee devices west of it. But if I just move it 90° to another wall, everything works perfectly. Sometimes doing as little as moving a device two or 3 feet in one Direction will make a difference. But this is all pretty much trial and error.
G) some more expensive zigbee coordinators use what is called “channel agility” and can change the channel they are using on-the-fly if there is too much interference. The SmartThings hub does not.
H) The Phillips hue bridge allows you to change its channel whenever you want. Your Wi-Fi router probably does too. The SmartThings V1 hub could not change its channel at all after it was manufactured. The SmartThings V2 hub can change its zigbee channel, but only if you do a factory reset and lose all your existing information, and the channel is reset randomly so you can’t specify what the new one will be and you might even get the old one again.
So there are a lot of things you can try, but Nothing guaranteed.
Short Answer
The best configuration is usually to make sure the Wi-Fi router and the SmartThings hub are at least 10 feet apart, and use Wi-Fi on channel 11, SmartThings on channel 11, and the Phillips hue bridge on channel 25. (See the diagram in post one of this thread – – Zigbee channel 11 and Wi-Fi channel 11 are about as far apart as you can get.)
Unfortunately, however, since it’s not easy to change the SmartThings channel and it doesn’t use channel agility, you may have to go through all the steps above if you’re having interference problems.