Zigbee mesh problem with Stelpro Ki - Zigbee edition

I have a strange zigbee problem since few weeks in my home.

Most of my devices were zwave until few weeks ago and I never got any problem with them… I mostly have Stelpro Ki thermostats running on zwave and few leviton switches, zwave too.

The only zigbee devices I had was those coming from the starter kit and few water leak detector I bought.

Everything was working fine… yet.

Few of my collegues were successfully using cheap Xaomi Zigbee devices from AliExpress, so I decided to start using them too. I bought few Xaomi sensors and Heimantech Smoke detector (I even published a handler for them). At the same time I was needing to replace 2 thermostats, so I decided to buy the Zigbee version of the Stelpro Ki to help improve the Zigbee mesh network for my new sensors.

I installed everything… and it works correctly. At the exception the devices started disconnecting after few hours/days. None of my new sensors were acting correctly. I was pretty annoying.

I suspected it was a problem with the Zigbee mesh, so I decided to “repair” the mesh network. I read the best way to do it is to shutdown the hub for few minutes. I did that and… I lost most of my zigbee sensors even those which was working correctly before.

After a lot of investigations, I decided to turn off the zigbee feature on my 2 “zigbee” Stelpro Ki and… after few minutes all my Zigbee devices connected successfully to the hub!!

So… it seems there’s a problem with the Zigbee edition of the Stelpro Ki when they are acting as repeaters in the mesh network… Anybody knows how to fix that??


Problem is fixed by adding more powered zigbee devices acting as repeaters.
I bought few ECOSMART Connected LED Light Bulb from Home Depot and
use the ZLL xxx Bulb handler and the problem is now solved.
There is absolutely no problem with Stelpro Ki devices: they are working great!


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Hi @carl.debilly,

I’m sorry that you are having issues with your zigbee thermostats.

Our Stelpro Ki ZigBee thermostat is zigbee certified, so I don’t expect any “wrong” behavior, however, there is a limitation to the number of “child” devices that may be connected to our thermostat.
In short, it means that a single thermostat cannot be the repeater for every devices in a network.
For instance, if you planned to use a Ki Zigbee thermostat to extend the network to let say (I’m just putting numbers here) 10 other zigbee devices, these devices won’t be able to get connected to the network because the thermostat’s routing table will be full.

The thermostat won’t tell the user how many child devices are connected to it, as it may change during the life of the zigbee network. So it’s hard to know how the network will behave in large and extended setup.

Since you made handlers for other zigbee devices, can I assume you have access to a zigbee sniffer?

If so, could you try to log the zigbee network activity and sent it to me?

To be honest, I developed other handlers using back&forth trying, I’m really not well equiped for developing more seriously with Zigbee. It’s a hobby for me but my day job is a software architect - so I’m highly interested to improve my tooling and knowledge.

Could you recommend me a good sniffer I can buy ? I definitely want one to reduce the required time to develop a handler ;-).

For the number of devices, we’re talking around 5-6 battery-powered devices repeating through two Ki devices.

By the way I really LIKE your company and your devices and I can’t wait for your new “Maestro” line of devices to come out on the market, hoping it will intergrate well with ST. I’m from Montreal, by the way ;-).


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Hi @carl.debilly ,

I would recommend an NXP dongle (JN5169) as the hardware component in combination with the Ubiqua Protocol Analyzer from The Ubilogix company.

You may buy the dongle on DigiKey with the following part number: 568-13052-ND NXP Dongle at DigiKey Canada
You may request a sniffer license (a trial is also available if I recall correctly) at the ubilogix website: Ubilogix

It seems to be the best for a professionnal development. I suppose that’s your tooling. Do you know any “hobby level” equivalent of the software.

What do you think about the TI’sCC2531EMK http://www.ti.com/tool/CC2531EMK ? the software seems free…


Well, I don’t know the other tool.
The NXP dongle doesn’t not cost that much more either.

You may check out that post:

Finally I bought few zigbee devices at Home Depot and everything seems to work properly now. I bought few “ecosmart smart bulb” (very affordable bulbs) and few more Stelpro Zigbee thermostats and… everything is back to normal.

Thanks for the help… So now I understand having repeater devices in range is not enough when you have too much battery-powered devices. You need to keep a certain ratio between battery devices and powered devices.

Thanks JF for your good help.


Hi @carl.debilly, thanks for writing up this thread - I am experiencing similar problems:

A few years ago I installed 1 Stelpro Ki Z-Wave and 3 Stelpro Ki ZigBee thermostats in my parents home using the device handlers posted by @gouroufui . I went overseas and returned a few months ago and I saw that SmartThings now officially supports the thermostats. I reassociated all of the thermostats to the hub using the new SmartThings app and the corresponding Stelpro handlers and everything worked great for a few days. However after a few days all 3 zigbee thermostats lost connection (within an hour of each other). I did a factory reset of all 3 and also set the hub to allow insecure Zigbee rejoins (in case that was the problem) and the 3 thermostats stayed connected for about a week and then all 3 lost connection around the same time. I disassociated and repaired all 3 and they stayed connected for 24 hours and then disconnected again. I have Zigbee outlets nearby each of the thermostats and between them and the hub - everything (including Zigbee devices further from the hub) stays connected without problems except for the 3 Zigbee thermostats. I think now they seem to stay connected for 4-7 days before disconnecting. The Z-Wave thermostat hasn’t had any issues.

Do you still have your Stelpro Ki Zigbees? Have they been working ok since your last post? Are you using the handler that @gouroufui created or the ones built into Smartthings? Thanks in advance for your help!