I’ve been struggling for the past month trying to migrate from V1 to V2. Unfortunately, my Z-Wave mesh keeps getting corrupt and I now get the dreaded “Err 101: ZW module not responding” every five minutes.

The first time this happened, support sent me a new hub assuming it was a z-wave radio issue. So I have been sloooowwwwllly adding one device at a time and doing a repair after each. I got up to 100 and boom, it went corrupt again. Tying to fix dropped devices individually once it gets to this point is like playing Whac-A-Mole; another one or two drops in the next repair.

I’ve looked though all the other threads and it seems the best I can do is remove everything and add them back again. One thing I noticed that others did not mention is a “Failed to read protocol info” error showing up in the log randomly before a ghost device. However, I’m to the point it is not worth it and just junk it.

There is obviously a bug. It is frustrating that SmartThings is not able to manage the routing tables. Why don’t they expose them to the user? We could then help diagnose on our own and help repeat and/or isolate the bug. We need to be able to create a snapshot of the tables before and after including, excluding or repairing. If they go corrupt, then we should be able to just roll back to the previous. If corrupt, we can compare the differences and help determine the issue. In fact, why not automatically keep snapshots that can automatically roll back when corruption is recognized?

I’ve always advocated that if we could see signal strength in routing tables we could better understand where to place devices or repeaters or what may be causing interference.

Please tell me an engineer is working on this now.


I dodged the bullet once by removing a recently created ghost. If you cannot identify the ghost, contact support. @bamarayne has had luck with them cleaning up ghosts/orphans. I wasn’t successful. But I was lucky to try to include and then exclude a GE outdoor outlet that was hanging in the tables. Once I cleared that one, my err 101 went away.

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When I’ve rebuilt my system I’ve always started with the device closest to the hub and worked my way. I would do a zwave repair every ten devices.

That worked really well for me.

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I did this same thing minus the zwave repairs.

I believe I did zigbee first - I did all repeaters first, then worked my way out
Then zwave - repeaters first and then worked my way out
Finished with LAN and cloud


I think @JDRoberts has said as well that it’s better to go in repeaters first and then add devices spreading out from the hub.

That way you already have an established ‘backbone’ mesh for devices to see as they get included.

I’m worried I’m going to run into this issue as well at some point as I am 99% Z-Wave with about 45 devices or something and about another 60-70 to add. That being said, I wanted to do it spreading out from the hub as people have suggested but I never did, I just started randomly throwing them in even blinds that are like 50ft away from the hub, behind several walls worked just fine.

I did run into a couple of issues but they turned out to be signal and as I added more devices, it stabilised. I know there is a hardware limit to a Z-Wave mesh but I thought it was over 100 devices anyway, @beckwith are you saying when you hit 100, it definitely changed then?

Here’s the FAQ on fixing zwave repair error messages if that’s of any interest:

And, yes, I build the backbone first because that way the battery operated devices will be able to find all the available repeaters when they build their own address tables. Sometimes the best repeater is one floor up, for example. But if you want to go room by room and then do the repair utility at the end, you can.

One thing to note – – there is a huge difference between Z wave plus and earlier zwave generations. Zwave plus is much better at pairing in place. Even so, the device doesn’t know that a repeater exists unless either that repeater was on the network before the battery operated device was added or until you’ve done a repair.

As far as Max devices, the Z wave standard itself limited network to 232 nodes including the hub.

But there have been various smartthings – specific issues in the past at both 100 devices and 200 devices, but some of those applied to a specific device class. I honestly don’t know what the current status is on those issues.

My personal rule of thumb is that if you run the zwave repair and you get errors on 10% or fewer of the devices, then fix one device at a time.

More than that, and I start looking at it as a damaged network. Typically I would first remove any devices added in the last week. Then take the hub off power for 15 minutes and then restart it, just to get it synced up again with the cloud account. Then then run a repair and see if that got rid of the problems.

Otherwise, I would look for a failing repeater than a number of other devices were trying to use.

But if you’re above that 10% threshold it just gets to be trial and error no matter which thread in the tangle you start pulling on first. :disappointed_relieved:

Hi @beckwith,

While I posted this for a v2 to v2 migration, it should still apply for a v1:

Zwave repair is very important. In fact, I haven’t done a zwave repair in many months, even after adding a couple over the last couple months.

Thanks for all the support and suggestions. I appreciate the SmartThings community.

I’m afraid this may be the last straw for me, however. If I load these from scratch again, who is to say it won’t happen a third time. Who wants to go through this again. And I’m to the point where I don’t even want to look for alternative products.

Seems like addressing this isn’t even on SmartThings radar. I just don’t see IoT being robust enough for the consumer market for some time. Issues like this take existing people out of the market and discourage others from entering. I know I can’t recommend it to others, unfortunately.

I’m really sorry that you’ve run into these issues. I did want to say that I think you’re absolutely right as far as “inexpensive full-featured IOT systems.”

If you have the money, a control 4 system is very robust with lots of features. But it typically costs about 10% of the price of the house plus ongoing annual fees.

If you’re willing to go with a limited feature system, there are several very popular ones on the market that work just fine and are very reliable. The Phillips hue bridge, Lutron Caseta, Logitech Harmony, Indigo (zwave), Apple HomeKit. None of them can do as many things as SmartThings does, but they all have much longer maintenance free operating periods.

So it just comes down to what you need and if you’re willing to use more than one app to get it.

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