Minimum Number of Devices for Zigbee Mesh Reliability?

As subject states, what is everyone’s opinion on the minimum number of devices required for a good mesh network.

In my home, I have my ST hub centrally located in the laundry room. Now my house is L shaped and the laundry room is in that central corner. All of my switches are Z-wave - great network, but only z-wave. All of my sensors are zigbee, hence the issue. I would like to add a few zigbee repeater appliance plugs, such as these:

My goal is to get better reliability out of my zigbee sensors and reduce the battery life. I’m hoping to get better detection of my wife’s presence sensor.


This is discussed briefly in the wireless range FAQ. It’s less about how many than it is about distance.

It’s also important to note that it is up to each manufacturer to decide how many children each zigbee repeater can support.

The smartthings hub can support 32 directly connected zigbee end devices. Others zigbee repeaters tend to support around five, but some might only be three where others might be seven or even more. It does require some memory and processing power to handle each child, so there is a cost factor even if it’s not much.

All of which is to say if you try to put 33 Sengled element lightbulbs ( which don’t repeat it all) in one room with the ST hub, one of them will keep falling off Until you add an additional zigbee repeater in that range.

Speaking just for myself, I try to put two repeaters of each protocol in each room. That should be way more than enough, and it gives me a very strong mesh.

At a minimum, with typical US construction, you will need one about one every 40 feet. If you live in a house with brick or adobe walls, you might need more.

Zigbee is an Omnidirectional signal, which means you can count that 40 feet as the radius of a sphere around the repeater device. :sunglasses:

Also note that zigbee home automation, (ZHA), which is the profile that smartthings Uses, is limited to 15 hops into the hub and 15 out. As a practical matter, that will not affect most residential buildings, but again if you have brick or adobe walls it might.

{as mentioned previously, I was a network engineer and had worked with Zigbee and Z wave devices before ever buying SmartThings for my own home.}


Thanks @JDRoberts, I was trying to find something on search but did not see anything ‘obvious’. The device counts help a lot. I currently have only 12 devices on Zigbee, but Im heavy in the front of the house. I may just do one repeater per main room, so 5 downstairs and 3 upstairs.

This is the specific device I am looking at:

It allegedly repeats both zigbee and z-wave, so if true, replacing existing z-wave plugs with this should not penalize me.

The Iris Plugs is what I use but never did the z-wave option as I have GE Switches in each room. You can sometimes catch them on sale at Lowe’s.

Altogether, I think I have about 20 of them and never had an issue. They are also super useful for HA as they measure power usage.


I have tons of zigbee devices, and I have at least 1 repeating device per room. I specifically use that Iris device, but I don’t enable zwave because I already have tons of those too. Adding several repeater devices in my environment was single handedly the best thing I could have done for my Zigbee mesh.


I only have a few Iris plugs, 3 to be exact. They work great and will be my go to device when I add more sensors and need more mesh.

When I mapped my Zigbee mesh the Iris plug upstairs alsmost directly abouve my hub was the go to favorite for many of my Zigbee devices and repeaters. Including the Xbee radio approximately 80 feet away in my shed.

Sometimes an Iris plug would even work across that gap from the shed to the Iris plug upstairs.


Thanks everyone for the replies. I have about 30 switches I think, all GE Z-wave so all repeating. I have about 10 more to add. Im also undecided on ceiling fans, but this could potentially add 5 more z-wave devices if I go that route.

Just the zigbee mesh, I am short…none actually. For christmas and other holiday decorations, I have 6-z-wave GE appliance outlet plugs, one at each window…which is basically one per room except the two rear bedrooms, so my plan is to swap these with the zigbee ones. I probably sell the z-wave ones on eBay or something to help pay for it.

Thanks for the input, I have a plan now.

How did you map their route?

Okay I was ALL over the place getting info and getting it to work.
I started in this thread and ordered the parts in this post:

If you scroll down to post 87 in that thread is where I jumped in and started posting.

Here is the thread on the FAQ on mapping your Zigbee mesh:

Here is another thread where I jumped in and did some postings with my efforts and results:

Any questions? PM me and I will try to help or start a thread and I will gladly jump in and try to help.


Also note that some zigbee devices don’t work with repeaters, like Xiaomi.

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The ones that don’t work with other ZHA repeaters, though, should only be those that are not using the ZHA profile. The original Xiaomi devices are popular because they very cheap, but they are not certified to work with anything except their own controller. So they do have some idiosyncrasies.

Thanks for the heads up on that. I’m pretty sure I’m safe though if I am using Iris zigbee sensors and Iris outlets for the repeaters. I suppose I could be wrong as they just rebrand other products. But I am assuming Iris has already streamlined compatibility since they run such a closed system that anything branded as theirs should work together. I have to say that while I was never impressed with their hub, their products seem to be rock solid.

yeah, Iris is good since it ZHA 1.2 certified. I have a house full of them.