I have a pair of LG bulbs (model B1027EB0Z02) that I bought in 2015. They are Zigbee (not Z-wave), and for about five years, I could dim them to any level of brightness with SmartThings (and by extension, with Google Home or Alexa), connected with my SmartThings v1 (2013) hub.
Sometime last year, the bulbs could no longer be dimmed. They basically behaved with on/off only. If I use SmartThings to try to set the dimmer level to a specific setting, the slider immediately pops back up to 100%. If I ask Alexa or Google home to dim the bulbs to a specific number, I get an affirmative chime that the setting has been changed, but the bulb stays at 100%.
I had hoped that this behavior would be fixed when I upgraded to a new Aeotec SmartThings hub, but I have seen no improvement. Any ideas on how I can restore this capability? I’d like to get these Zigbee bulbs fixed and working like they used to.
That’s a mystery. I’ve had some similar behavior, but nothing that power cycling or re-pairing the bulbs wouldn’t fix. But considering you have upgraded the hub, and the problem persisted, that doesn’t seem to be the issue.
I’m curious how Smartthings recognizes the bulbs, and if you have tried using another DTH (device type handler) for the bulbs?
Hi James,
Thanks for chiming in on this. Currently when I log into the Graph API for SmartThings, it shows the device type is ZigBee Dimmer, which I believe is correct. I noodled around with changing it to other device types but nothing seems to work. I guess the bulbs aren’t completely useless since they still work for on/off, but I do like to be able to change the brightness from time to time.
If I recall correctly, I did browse the subject of LG Zigbee bulbs on the Hubitat forum. I believe the consensus was that they worked with the addition of a Hue Bridge. I’m imagining the same case with Smartthings. It’s just odd that they would stop working from one ST hub to another.
Again, someone may turn up with a definitive answer. If I come across one, I’ll be sure to follow up.
That’s a very old device and it uses the ZHA profile, not ZLL or Zigbee 3.0. I’d be very surprised if it works with the hue bridge. 
I would look through the choice of DTHs and see if there is one specifically for ZHA, I suspect the non-dimming is because of incompatibility with some zigbee 3.0 clusters.
Thanks very much for the clues. I may be headed in the right direction here. It does not look like there is a default option for ZHA among the DTHs offered. However, the graph.api.smartthings.com site does give me the option to create my own device handler. Is that what I need to be doing? I see something about a Zigbee Dimmer, with a number of manufacturers offered as option (Leviton, etc.), but nothing for LG. Do I need to create the handler this way?
Gotta admit, I’m wading into waters I am very unfamiliar with. I kind of solved my problem already by just buying new $10 bulbs to replace these $25 ones, but I’m also feeling a little bit stubborn about the planned obsolescence of perfectly functioning devices after only 4 years of use (they stopped dimming in 2019 or so).
After JD offered the information about these LG bulbs being ZHA, I did another search and came up with this thread.
I think it’s suggesting that ZHA devices mixed with Zigbee 3.0 is bad for you network. I can’t say for sure, but interesting reading.
I don’t want to give you bad advice here, since I can’t even read the code let alone know what smartthings would require. Also I don’t know whether the DTH Has to have the correct manufacturer code in it now, or not.
What DTH are you using now? I would expect something that works for a basic cree bulb to also work because that’s also a ZHA device, unless, again, smartthings requires a manufacturer code. 
Tagging @johnconstantelo in case he has anything to add.
For what it’s worth, the Cree Bulb DTH only has one fingerprint (Cree), but works with my Sengled and Ecosmart bulbs. So, at least it doesn’t seem to care what bulb is using it.
Here’s a link to the Cree DTH, Ehren, if you decide to have a go at modifying it, or maybe it might work automagically.
It’s a more technical discussion that that, and it was written at a time when the ST hub didn’t support Zigbee 3.0, so different world.
It’s generally fine to mix ZHA, ZLL, and Zigbee 3.0 devices on the same network with the following caveats:
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it’s best if your hub supports Zigbee 3.0 if you’re doing a lot of mixing (ST now does)
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ZLL bulbs may be poor repeaters for ZHA devices. There’s a whole FAQ on this:
FAQ: Are Smart Bulbs Repeaters? (Updated 2019: the new answer is yes, but may be inconsistent)
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the hue bridge forms its own mini Zigbee network for devices attached to it, so those devices then don’t repeat for other devices attached to the ST hub. This can be a good thing because it gets those ZLL devices off the ST network.
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ZLL and Zigbee 3.0 devices will fall back to a ZHA profile when attached to a ZHA-only hub, but this can have some quirks. This was a big issue for ST customers until the V2 and V3 hubs were updated to Zigbee 3.0, so there are a lot of old forum thread discussing those issues, but they no longer apply.
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some manufacturers push the edge on their Zigbee implementation, meaning their devices don’t work smoothly with those of other brands, even though they should. Xioami Is famous for this (for example, they don’t work well with all repeaters). IKEA occasionally has this issue. It’s probably not a coincidence that these are budget brands.
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some Zigbee features are optional for manufacturers. For example, the ST V3 hub now supports Zigbee 3.0, but does not support touchlink commissioning or the green power clusters. So the Hue tap cannot be directly added to an ST setup, for example, nor the RunLessWire or Senic batteryfree switches.
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there are some security settings which prevent devices from other profiles from joining an existing Zigbee network, but ST does not at the time of this writing use these, so it doesn’t affect an ST setup.
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FAQ: Zigbee Application Profiles, or why not all zigbee devices work with SmartThings
So…it’s generally fine to mix ZHA, Zigbee 3.0, and ZLL devices on one Zigbee network as long as the hub is Zigbee 3.0, with the understanding that some specific models may have some issues, and that most lightbulbs are not good Zigbee repeaters except for other Zigbee lightbulbs. (IKEA seems to be the positive exception here: historically their tradfri bulbs have been good repeaters in an ST setup.)
Zigbee 3.0 is intended to be forwards and backwards compatible, it just doesn’t always succeed.
Brief discussion:
Official white paper with more details:
Tagging @garrett.kranz just because he likes stuff like this. 
Good info!
So, ZHA isn’t quite the forgotten ancient relic that I was imagining.
I don’t think many manufacturers are making new models using ZHA (it’s almost all Zigbee 3.0 now), but there are plenty of older ZHA devices still in service, quite a few still being sold from old inventory, and even a few models still being manufactured as new stock.
Osram/Sylvania made the decision recently to shut down their cloud services rather than upgrade all their devices to 3.0, which may be where you got that impression.
Furthermore, the implemented ZigBee® standard is not state of the art anymore (ZigBee® Light Link and ZigBee® Home Automation instead of ZigBee® 3.0) which makes it more and more difficult to ensure compatibility to other smart home systems.
But “more difficult” isn’t “impossible,” and they aren’t recalling the devices, just shutting down the cloud service.
Eventually Zigbee ZHA devices which can’t be updated to matter compatibility may become obsolete, but we’re a ways off from that yet.
Speaking just for myself, if I were buying a new device, I’d be looking for Zigbee 3.0 . But I’d continue to operate any existing ZHA devices that I had that were working fine as installed.
If ZHA devices were truly obsolete, I would surely have several dozen…
Just an observation comparing the Zigbee Dimmer vs Cree Bulb DTH. The cluster mappings, if that is the right word, looked very different. I’m not sure if that has to do with the Cree being ZHA or not, but I mention this in case someone might offer some insight, which might help getting the LG bulbs working , if the Cree handler doesn’t solve the problem.
I do have a box full of window/door sensors (although not ZHA) that don’t respond to any of the available DTH. I hope to get them working as my understanding of clusters and such improves.
This is all very intriguing banter. I did not know there were so many different Zigbee standards floating around out there.
I would just add one more tidbit here about my specific situation: the V1 hub I was using (right up until Samsung finally killed it off on June 30) also had problems with the LG bulbs and dimming. Sometime in 2019 or so, the ability to dim the LG bulbs just stopped, and they became on/off bulbs only. So the problem predates my installing the new Aeotec hub. Did Samsung/SmartThings release a software or firmware update that dropped support for the older Zigbee Home Automation standards or something?
One standard, multiple “profiles.” Bluetooth also does this. Zwave does not.
Did Samsung/SmartThings release a software or firmware update that dropped support for the older Zigbee Home Automation standards or something?
Not that I know of, but I think they did update a bunch of their generic DTHs so they would be assuming the device was Zigbee 3.0 rather than assuming it was ZHA. But again, I can’t read the code, so I don’t know if that’s really an issue or not.
What DTH are the bulbs currently using? and again my first suggestion would be just to try the existing Cree DTH and see if it works.
When I first paired the LG Zigbee bulbs with my new Aeotec hub, they were recognized with a DTH of ZigBee Dimmer.
I just tried changing them to Cree Bulb and the behavior did not change: they can be turned on/off but not dimmed. When I slide the dimmer slider in the SmartThings app for the bulbs to anything above zero or below 100, it immediately snaps back to 100%.
Were these bulbs working fine using the Zigbee Dimmer DTH earlier on the V1? Sorry just catching up on this discussion.
Possible DTH candidate could be Sylvania Ultra IQ.
Just stabbing in the dark on a rainy day.
Yes, until sometime in late 2019/early 2020, these LG bulbs were working fine with the SmartThings v1 hub. I am not 100% sure that they were using the Zigbee Dimmer DTH; since they “just worked”, I didn’t really investigate any of the underpinnings. But it was probably using that device handler, yes.
James,
Your suggestion to select the Sylvania Ultra IQ worked! Both of my LG lights now dim on command (Alexa voice or using the ST app)
Thank you very much for your help!
Ehren