I'm moving in to a house with a Vista 128BPT burglar alarm and I'd really like to add smoke/heat and CO detectors to the system.

However, I also really want the smokes/heat detectors to be on individual zones, or at least zoned per floor - it's 3-level house plus attached garage, with gas HVAC units in basement and attic. If the system triggers, I really don't want to have to search the whole place to find which one tripped.

I know that Honeywell makes a V-Plex addressable smoke that I could use (5193SD), but it doesn't have a built-in sounder and I would really like to avoid having to also install separate sounders, both in terms of having to pull more wiring and in terms of having yet another thing sticking out of the wall/ceiling.

I understand that if I set up 4-wire smokes/CO as separate zones, (1) I'd use a single trigger relay to reset them and it would likely cause a trouble on all of the zones that weren't faulted but got reset, and (2) I'd either need an EOL relay on every zone, or to use smokes with built-in EOL relays (only a few I could find, and rather expensive), or to run 5+ conductors to every smoke so that I could home-run everything but still daisy-chain the power. I also understand that to get one-go-all-go with this setup I'd need a reversing relay (e.g. System Sensor RRS-MOD) driven from a relay on the panel (4204 relay module) and programmed to trigger the relay when any of the fire zones fault.

Is this all crazy for a residential setup? Is there a simpler/more straightforward way to achieve my goals, which are in order:

  1. Know exactly which detector faulted
  2. One-go-all-go
  3. Detectors with sounders built-in
  • "Is this crazy" is a matter of opinion, which is explicitly off-topic.
    – FreeMan
    Oct 19, 2023 at 14:15
  • If your insurance company knows about the alarm system and has baked that into your insurance rates, they are the ones who need to answer this question. If not, you can do whatever you wish and whatever works, crazy or not.
    – MTA
    Oct 19, 2023 at 14:33

1 Answer 1


This is tricky but sort-of-possible

Given that you have a fairly standard combination (fire/burglary) panel, what you want is possible, just non-trivial. You'll be using System Sensor 4WTA-B detectors for smoke and heat with COSMO-4W CO/smoke detectors and a COSMOD-4W control module for each zone in lieu of a reversing relay, as these detectors all have integral sounders but need the COSMOD to help with temporal generation and the likes. You'll also need a 4204 quad relay module for your panel to both control smoke power (via a NC contact) and provide smoke & CO trigger outputs to the COSMODs (via NO contacts), as well as standard EOL relays (EOLR-1 or equivalent)

The bad news, though, is that your Vista panel doesn't support generating Temporal 4 output for CO zones. Furthermore, being limited to 750mA of 12V means that you can't put anything good for a separate device (like a Low Frequency sounder, or strobes for that matter) on the panel's sounder output, so you might as well just leave it connected to whatever burglary sounder is present provided current draw isn't an issue.

  • Thank you so much! I still haven't implemented all of this. This is a wonderful answer, but the cost of COSMOD's per-zone ... when I'd hoped to have every detector on its own zone... is rather staggering. I hadn't realized about the limitations of my panel re: temporal generation. Mar 23 at 9:53
  • @JasonAntman The COSMODs have enough smarts in them that you probably could get away with zone-per-floor without causing too much difficulty when it comes to figuring out which detector tripped Mar 23 at 20:23

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