Can "Honeywell T6 Pro Z-Wave Thermostat" report power loss?

Title pretty much says it all.


Not that I'm aware of - I have one and I've never seen an option like that. Capabilities from the built-in driver below. Bryan's driver doesn't add any option like power loss reporting IRRC.

I found the below in the Honeywell manual


Never mind, I found it. I should have thought of it sooner. Its accessible via a custom attribute.


This would be useful to show problem with hvac... (I mean if it switches to battery then there is a problem)

I looked on mine and it doesn't output that attribute.

Which driver are you using w/your T6?

The build in driver: Honeywell T6 Pro Z-Wave Thermostat.

So basically I have three "sensors" to announce lose of AC power. I will use one to shut down my hub an hour or so after power loss. My battery backup is good for 3 to 4 hours (maybe a little less if the battery is not fresh).

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Ahh I was looking for the attribute power source..doh!

Same! Tried "power" whatever...never would have found this w/out your sleuthing, @JohnRob, nicely done! :slight_smile:

Wow I never thought of it until you brought it up

Odd...when I go into RM and looked for devices that supported Power Source, only one device shows up, the three Aeotec Range Extender 6 that I have. These guys don't have a battery, so if power goes out they aren't going to report anything. Also not sure why you'd need both "mains" and "dc." Strange, right? Or am I missing something?

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There is a use case for "dc" v/s "battery". For example in @iharyadi's zigbee arrival sensor for cars.

Thanks. I get that, but how is "dc" different from "mains?" I don't get that, seems redundant.

Aha. Conventionally wouldn't mains be "ac"?


I'm in the US but having participated in differernt HA and electronic forums I've adopted the use of "mains" as an intuitive (to me) name for the "AC" power coming from the power company or generator. I guess now a Tesla wall battery would be included.

I think it exudes a higher level of danger than AC although I can't quite put my finger on why it seems that to me.

As for why there are seemingly redundant sources. I guess it was easy and didn't consume any additional resources. OR perhaps I have no idea :slight_smile:


It's just the attribute they have in them. My aeotec's are the same what but my thermostat and my ring v2 extender show up too and I can confirm the thermostat changes to battery when power is cut to the hvac.


My T6 is running on battery only right now (not hooked up to HVAC, testing/playing w/it) so that's likely why the Power Source attribute isn't exposed. It also blocks the option to turn off dim on the display when only on batteries, so they do appear to have features they limit when not on mains power.

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If only one of the members of AC/DC were here to explain... :wink:

Oops...meant "mansplain." :smiley:

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If they were here, you can bet they'd have the balls to step up and do it.

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Download the Hubitat app