Smoke Detector Help


Senior Member
My smoke detectors falsed again today. The most recent change was to add another detector at the end of the line. It had been up and running without issue for a month prior to that.

As such, I am guessing it is related to the new detector, but I'm not sure how to narrow it down other than to disconnect that one (which then I don't know what the issue is).

I have System Sensor i3 2WTA-B (2-wire smokes) detectors (5 of them installed, one of them in the last week) which are connected to a RRS-MOD (reversing relay) then a 2W-MOD2 (cleanme detection essentially, and 4-wire conversion) and then to the Elk M1G.

The 2W-MOD2 reports that it is communicating with the detectors (and has the capability to report a wiring fault, which is not activated).

I have been home when it has falsed, and I have seen no indication of smoke, or excessive heat. I went to each detector to see if the red light was active and I did not see it (hoping to find which one activated it, but I also think in hindsight I did not watch it long enough).

Anyone have any thoughts on troubleshooting this? I seem to blame the new detector (in some way), but what is the best way to resolve the issue?

I'm going to try cleaning that detector, but any other thoughts would be appreciated.

EDIT: I also redid the walk test, which was successful at all detectors. I see they have a SENS-RDR ( to measure the sensitivity. Perhaps that might be something worth looking into.

EDIT: I've taken it apart and cleaned it (although if that is what was needed, I would have expected the 2W-MOD2 to notify me ideally, although I saw some posts on it being hard to get it to a clean condition in general). I'll see how it goes.