Negative effects of ZWave repeaters on locks and other ZWave devices?

Lots of threads here advise to add ZWave repeaters to improve on ZWave locks stability, but I have a reverse question. I stumbled on a user’s report on Amazon that ever since adding a GoControl ZWave thermostat in the repeater mode it made his smart lock drain batteries, possibly because the thermostat broadcasts frequent updates on temperature changes... I also have a Zwave lock and I don’t have any issues with it, it’s close to the hub and no need for a ZWave range extender. I’m about to install the GoControl ZWave thermostat, and I wonder if I would be better off adding it in the non-repeater mode in my case (by adding it before I connect it to the 24V wire).

In other words, if I don’t have any issues with my ZWave devices today, why bother adding a ZWave repeater and bring unnecessary risks to my already stable network? Do Zwave repeaters improve on the connectivity at the expense of draining batteries faster? Any opinions?

It will be interesting to hear what experience others have had with this. If I was in your situation, I would test it out - see how long my batteries last without it on repeat mode, and then with. Not a scientific test, but if there is a huge difference, you get to see what works best in your environment.

Sounds like an opportunity for GoControl to send an update :smiley: It's a flaw in the device in my interpretation. If it's acting as a bad repeater, it is 'broken' :slight_smile:

Repeaters don't do anything to the messages. Classic data in/data out, in the sense that the repeater doesn't look at the message (other than to get the pre-defined next hop from the message.) Doesn't matter if the message is encrypted or not, it's just a string of 1's and 0's. That's the intent anyway. If anything else is occurring, it's broken and needs to be disabled or removed from the mesh and sent back. :slight_smile:

GoControl is a Nortek brand... same as Linear and one other I can't remember off the top. I have a Linear Garage Door Opener (GDO) and it's done a fine job of repeating for several years. In fact, when I got my first C-7, everything I migrated over used the GDO to repeat. So they know how make a repeater :smiley:

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All Z-Wave repeaters are mains powered devices only. Battery devices don't repeat. The main benefit of having a Z-Wave plus repeater near a lock is they can store and forward packets. That makes it less likey to miss a message sent from the hub when the lock is taking a nap.

To be clear - this is what that "report" on Amazon says:

"I have two battery powered zwave door locks. Since installing this, the lock batteries die in two weeks. Does this unit constantly send out a signal?"

Here's the interpretation you applied:

This interpretation is unreliable for a few reasons:

  1. There's no indication the person on Amazon connected/paired the GoControl t-stat when it was 24VAC powered, where it functions as a repeater, v/s when it was battery powered (when it is a FLiRS device).
  2. There's no evidence from the person on Amazon that the observation with their locks and the addition of the thermostat is consequential as opposed to being coincidental.
  3. We know nothing about the rest of their z-wave network with respect to the nature of the z-wave controller, the number of devices, the number/type of repeaters, their geometric location vis-a-vis the z-wave controller (and the thermostat, and the locks), the robustness/speed of the z-wave network.
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Voodoo Science. Good book, too.

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Yes I get that, repeaters are not on batteries. I meant, could they drain other devices' batteries, by sending extra messages that prevent other devices from sleeping. Or, in this case the thermostat being both a regular device and a repeater, could it be that every time it sends a temperature update intended for the hub that message also wakes up the lock?

I know nothing about Zwave implementation details, I was just trying to figure out possible logical reason behind the Amazon comment.

The issue has always been that "Home Automation" while seemingly simple on the surface is actually incredibly complex underneath. So many factors in making things work properly that it really is a testament to the staff/engineers at Hubitat Inc. that HE is as reliable as it is.

  • Wireless protocol mesh issues
  • Device implementation of those protocols.
  • Protocol differences or compatibility (various implementations of Zigbee etc).
  • Device/hub location and structural barriers
  • Radio interference from other devices like WiFi router or cordless phones or even appliances like microwaves
  • Radio chipset issues
  • Faulty Devices
  • power / electrical issues
  • Hub or device overheating (due to overcrowding in gang box etc).
  • Poor mesh strength
  • Poor rule implementations
  • Custom Apps/Drivers causing issues
  • Hub Firmware issues.
  • Local Network issues.
  • "Cloud" issues if using cloud devices or apps.
  • Legacy Z-Wave devices and polling issues.
  • Z-wave 700 series forced SO for non-S2 devices that support security.
  • Z-wave issues with beam forming (or lack thereof) when trying to pair locks etc.

Just to name a few... :wink:

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No, it doesn't send messages to the lock. It would send those changes to the hub.

For the Amazon post, my guess is the Thermostat was having communication issues while it was operating as a repeater and was causing the lock to constantly retransmit. But who knows really, people do screwy stuff sometimes without knowing the consequences and we don't really have any details about his configuration, or if he possibly introduced ghosts into the mesh, interference issues etc...

Most of the posts about devices not working correctly I see on the comments section on Amazon are usually easily fixable but they just don't have a good enough understanding about what is going on.

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Thanks for educating me, very helpful.

Quick follow up: where can I check if a particular device has joined as a repeater or not? I checked device properties in HE for some of my Zwave devices, but I don't see such parameter listed.

I plan to install the thermostat as a non-repeater first. I assume I can later remove, reset, and re-join it as a repeater if needed.

A general rule of thumb is if the device is solely battery powered. It is NOT a repeater.

If the devices gets it's power from a mains power (plugged in) then it IS a repeater.

This is completely device specific, as there are devices such as the zooz z18 (i believe) motion sensor that once you join it as a repeater (plugged in) it can no longer be joined as a battery device (non rerpeater)

Thermostats hooked up using the c-wire are considered a mains power device (generally)

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What I want to do, insert batteries and join as a non-repeater, then remove batteries and connect the C-wire, so I use it as non-repeater but with main power.

That's interesting, are you saying that once it's joined in a certain mode, factory-resetting some devices will no longer restore them to the original state?

This more than likely is not possible, (generally) you don't get to select between being a repeater or not, it usually is pre-determined by what source is powering the device.

Yes as far as the zooz is concerned once it's been mains powered it is permanent from then after, I found this out the hard way as I don't remember seeing that in the documentation of the device, as I stated it's device specific.

The above device you could join as a battery powered then later re-join it as a mains powered repeater. But once you joined it as a mains powered repeater you could no longer go backwards.

Actually the manual alludes to a possibility of a similar scenario. They say Do not install batteries and temporarily power the thermostat from 24VAC to include onto a Z-Wave network. Shortened battery life may occur when 24VAC power is removed (presumably because it will continue as a repeater on batteries). I concluded that I can do the reverse and have it as a non-repeater but on mains power, and I assumed just changing the power source would not make it automatically change the joining mode.

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This will work. I've done this with both the GoControl thermostat and the Honeywell T6 Pro Z-wave thermostat. Once the device has paired as a "non-repeater" (the term to use is "slave"), it will remain in that state even if the power source is changed.

Here are the details for my Honeywell T6 Pro to make it clearer:

As indicated in the screenshot below, the device is mains powered:

However, the device functions as a slave in the network and not as a repeater as shown below:

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If your hub is a C7, the following is an excellent tool for checking out what devices are used as repeaters.....

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I think so too.

Many people on Amazon give poor reviews to smart home devices when the underlying problem is user error in one form or another.

I don’t usually bother reading them anymore, unless it’s for a laugh :rofl:.

Great, thanks for confirming that. I don't want more repeaters on my network now, it's been fine. If I develop problems in the future, then I might rejoin it as a repeater.

No, I have the old hub. What's the easiest way for me check if a device is a slave or repeater?

I don't know.....I've only had the C7.

I usually just read them to see if there is possibly an underlying manufacturer defect. If I see evidence of a possible issue I dig further.

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