Zcombo $26.54 @ Amazon

First Alert Zcombo Smoke Detector


Oops, just saw this on the Black Friday thread. Sorry for the repost.

As someone who has these along with the smoke-only modules (ZSMOKE) through my house… I figured I would pass along my experience. They do come with some caveats. While the Z-wave integration is nice, expect to replace the batteries (2 AA) yearly in these. ST reports the battery at about 79% when they start chirping. They are send-only devices so you cannot forcefully poll their status or force them to alert when another siren goes off. The battery level is sent once every seven days approximately (FirstAlert could never give a definite time frame). CO is not reported separately – ST may show that it is separately monitoring but the device only reports a single combined ‘clear’ status. One of the smoke-only detectors does seem to randomly chirp on its own and sets off ST fire and occasionally eats through batteries. I attempted to get it replaced through FirstAlert but they simply said to just return it to the store (unfortunately I had already tossed the packaging).

Overall they’re nice basic sensors but with today’s smarter sensors they’re starting to get a little behind their counterparts.

Edit: clarification


I have several of these in my home, and they have been issue free over the last year or so

One question - I thought these came w/lithium batteries, which don’t need replacement for years rather than months. Maybe I’m mis-remembering…

I have a mixture of both Zcombo and Zsmoke. 12 in total ranging for 1 to 2 yrs. old. I’m using 2800mAh rechargable AA’s and change them every six months when the time changes regardless of their level. I do a systems test too. I haven’t had any false alarms. I’ve integrated them with several apps to flash lights, unlock doors, turn off HVAC and fans, voice and text alerts etc. I’m happy mine and pretty sure that they will do the right thing when needed.

So sounds like my memory is off then, these come w/standard AAs?

Mine are about a year old…I haven’t gotten any low-battery chirps and they are still reporting in to SmartThings. I’ll have to go around and test them. They all show at 100% battery in the ST app, which is not really possible after a year. :slight_smile:

I think standard AA’s are around 2500mAh Many AA rechargeables are less 1200-2000mAh

Mine all came with a set of two Duracell AA batteries. If yours are still showing 100% after a year, they’ve likely lost contact with ST. Don’t worry… it happens, sometimes frequently;)

I must be lucky mine have never dropped (that I can tell). All report battery every other day to ST. I have a webcore rule that checks all the battery powered devices daily and reports low level or no report.

I have daily reporting on all of them in ST app in the “Recently” tab, so it isn’t that they are disconnected.

I noticed the battery level is not actually accurate with the status report. I do test 5 of my detectors often and the the real level is only showed after the test. @tommyincville I like your idea of changing them out with rechargeable after 6 months.

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