First Alert ZCOMBO and NFPA/US Building Codes

From conversations with First Alert, it appears the ZCOMBO and ZSMOKE are not smoke detectors that can be used in the United States? The installation instructions clearly state where smoke detectors should be place, the minimum required, and the fact that according to US fire and building codes–when one alarm has a detection event–all alarms need to sound. However, the ZCombo/ZSmoke do not appear to interconnect.

Is it possible with a home automation hub to interconnect the First Alert ZCombo and ZSmoke? Can these detectors be configured within the SmartThings hub so when the test button is pushed on one alarm–all the alarms sound? This is a basic test done by any building or home inspector.

Does anyone have any experience with getting these detectors to interconnect? Thanks in advanced for sharing what you know.

the Zcombo don’t interconnect with each other. You can simulate an interconnection with a hub like ST and a seperate siren but you cannot make them all sound their own siren. Which sucks.

Even if you COULD make them all sound with a hub, I think it would be foolish to depend on it for life safety, and I don’t think it will ever meet NFPA/US Building codes.


Thank you for the quick reply!

Still scratching my head why a company like First Alert would make smoke detectors in this decade that don’t satisfy the basic code requirement. Even stranger having the code explained in their installation instructions.

Yanking out the First Alert stuff and looking for an alternative. Kidde’s detectors interlink but don’t work with SmartThings? Is there a Smoke/CO detector that interlinks and folks have had success using with SmartThings? (Kidde is attractive in that I can pick the units up at a local Home Depot.)

I’m not sure what building code you are looking at. Commercial buildings/multiple occupancy residences have a requirement for interconnect smoke alarms, but that is not a requirement for single family dwellings.

Edit: I guess it depends on where you are. Looks like NFPA recommends interconnected, but it isn’t required, but a lot of places require it even in single family dwellings. My local says they have to be hardwired as well, but I guess I was grandfathered because none of the ones in my house are hardwired.


Thanks again for the reply! My home is in North Carolina and a new construction. The builder informed me of the interconnectivity requirement–but after your post I did a bit of research. North Carolina does not appear to require interconnectivity, but I believe they do require hardwired. My builder indicated the first thing the inspector does on the CO inspection is push the test button and make sure all detectors sound.

Hope to get a Certificate of Occupancy on a new construction next week and just now figuring out, I probably needed to spend a bit more and get the Nest detectors. Nest and First Alert are the only smoke/co detectors that work with SmartThings, correct?

edit: Should have joined this community a few months ago! :slight_smile:

This might be completely wrong, this is from a 1 minute google search. I am in NY, it appears that the law states battery operated detector, except for Transient-Multiple Dwellings, and then they must be wired into system.

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There is a happy middle ground which might meet your needs: Add a bit of smarts to a dumb interconnected system. There are relay devices that you wire into the alarm interconnect which close when the alarm sounds. They’re designed to turn on an auxiliary siren or something like that, but you can also connect the relay contact into the auxiliary contact input on a door sensor.

I’m using the BRK RM4 with my First Alert alarms. For Kiddie alarms you should be able to use the Kiddie SM120X.

I’m using an Ecolink Contact Sensor, but any door sensor with an auxiliary contact input should work.

I added a custom device type to make the contact sensor appear as a smoke detector in the ST app. Now SHM gives me a notification if my alarm sounds, but the actual alarm system is hardwired, interconnected, and independent from any ST hiccups.

Search on the forums a bit and you will find several people that have taken this route and explained in more detail.


In addition to the national standard, there can be state and local standards as well. Your local fire department should be able to tell you the requirements. New construction will likely require hardwired. Massachusetts also has regulations for photoelectric and ionization sensors. Regulations are having a difficult time keeping up with the new technology, so many states are still catching up with things like wireless interconnect and mobile notification. There are a couple hardwired smart smoke/CO detectors in the works (Birdi and Halo), but they’re still working on certification. There’s also the Nest Protect, which has a hardwired option, but it only has wireless interconnect so it may not meet your regulations. Until then, to meet new construction requirements it’s probably best to use traditional alarms. To integrate with SmartThings, you can then wire in a relay or use a listening device like a Leeo or Kiddie RemoteLync. There’s lots of info in this community for all those options. Here’s a link to adding a relay (which I hope to do myself, some day).

The ZCOMBO works well for retrofit of older construction that doesn’t require hardwire or traditional interconnect, although it would be nice if they interconnected.


Actually, they can be configured to interconnect. Z-Wave provides for an ‘alarm’ function. I seem to recall this being enabled during my tests, but the next time I’m at the location where I have six of these, I’ll confirm, and if they are not configured as such, I’ll write a quick device type to remedy this.

Another instance where ST should really step up and add this to the default device type.


Slightly off topic, but would enabling the alarm function also allow other events to trigger the ZCOMBO as an alarm? For example, SHM detecting an intrusion alert.

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Will do some more searching through these forums. Thanks for the information–in three hours you folks answered questions I have been trying to get answered for a few weeks. Brand new to SmartThings–have gone through Wink and Iris–SmartThings is looking to have a lot more functionality.

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A z-wave network can have a variety of ‘alarms’ configured (water, temperature, smoke, co). I don’t trust smart home monitor, so I don’t use it.

That said, SmartThings has tried to abstract general smart home features to seamlessly interoperate various protocols, and as such, some specific protocol implementations aren’t utilized by default.

I purchased 3 of ZCOMBO alarms. It has been nothing but pain in the behind to have them recognized by V2 hub. I finally excluded them and after pulling the tray many times out was finally able to add them to ST. The challenge now is that they are all showing unavailable. I tried excluding them again, adding them again and they show good health but in a very short time they become available.

I tried the ZCOMBO DTH on GitHub, same issue. I tried both Zwave smoke and zwave basic but still the same.

The other challenge is that when it shows connected, I tried to lit up smoke, the alarm sounds but I do not get any alerts on my phone.

Do I return these piece of crap back to Amazon or is there something that I am missing?

If you have device health turned on, turn it off. My understanding is it’s much more trouble than it’s worth.

I have a v1 hub and have had no major issues with two zcombo devices in 2+ years.

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I also have the ZCOMBO and was able to pair fine. I used an Iphone and went thought the marketplace choosing First Alert Smoke Detector and Carbon Monoxide Alarm (ZCOMBO). Pressed the silence/test button to pair. No issued. I have device health turned on with mine.
While pairing the alarm was 2 feet from the hub. Installed after that 16 feet from hub. V2 hub with 25 other devices on it.
Hope this helps.

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Thanks for your quick response Mark and Jeff. Turning the device health OFF will be deceptive as you will not know if your device is connected to Hub or not. You should test your Smoke alarm by either pressing TEST or lighting an incense near the smoke alarm and forcing it to Turn it on; if you are not getting alert on your Phone you have a similar issue as mine. This is the only way to check the connectivity with the App.

I think ZCOMBO’s might have an issue connecting with the app, I have tried bringing them very close to the hub and even set them up near the hub. They paired finally but are showing disconnected in the device health (all three of them). It is most unlikely that all 3 Smoke Alarms are bad. I will wait to hear for a few more days if anybody on this forum is able to test their alarm or provide further input.

By the way, I have 40 plus devices added to hub that include GE/Jasco Switches/Dimmers, GE / Jasco Plugs, Philips Hue, Thermostats, Irrigation system and I have also added ADTPulse. Everything else is working fine.

I suggest you turn off device health to see if that resolves the issue (even if just temporarily).

There are other smartapps developed by community members that can help you track battery life on your devices, or alert you if a device hasn’t been heard from in some period of time.

My 2 Zcombo’s work fine with ST.

Mark, I can live with the health turned off. The issue however is that when I force the alarm to sound (which it does by either pushing the test button or forcing it to go off by holding smoke under it), there is no activity on the app on phone. The App should receive an alert or should go off. Have you tried to test the alarm by the above techniques and do you get an alert on the Smarthing app?

@marktheknife Mark, Did you get a chance to test the alarm?

Not in a long time. I tested two units when I bought them like two years ago, if I recall correctly they pushed an alert to ST when they detected actual smoke but not when I pushed the test button.