Fire false alarm trouble shooting

Last night my fire alarm went off while I was home and there was no fire. I’m worried about this occurring while I’m away from home. What troubleshooting steps can I take to find out what might have caused it to false alarm?

It reported a Fire Alarm: “the first floor smoke detector reported a fire alarm @ 7pm”. My concern is pretty obvious. I have had these detectors installed for a few months without any problems. They do not expire until 2020 if I remember correctly.


Has there been any work done in the area that may have kicked up an excessive amount of dust recently?

Placement of the detector is important. A few quick things to check:

  1. Inspect for moisture near the alarm device site. Water damage is a cause for all electronics to malfunction, however uncommon.
  2. Note the zone that tripped the alarm. 2GIG SMKT3-345 detectors are learned in as three separate zones. If it was the smoke loop zone that tripped, is the device near the kitchen or located above candles? Any dust from remodeling, repair?
  3. Any visible dust or cob-webbing on the device?

Another placement issue that may suddenly be causing trouble - Is the detector near a heating vent? I know some areas just got their first cold snap of the season, if your heat popped on for the first time that could be the culprit as well. This could cause the heat sensor to go off, and it could also cause trouble with your smoke sensor if the vent had a build up of dust that was pushed into your smoke/heat detector.

Jay - no dust on the detector


  1. No moisture anywhere near it
  2. It is setup for smoke, heat, and freeze on the panel. The alarm message reported “fire alarm” - I’m assuming that means heat? it’s located in an open area at the entrance to the stairwell. No candles near it and im pretty sure cooking didnt set it off. we have had a lot more smoke from cooking in the past and did not set it off.
  3. No dust or cob webs

Amanda - it is not located near any venting and we are in south Texas…it’s waaayyy hot. Heaters will not come on until November.

To determine which loop set off the alarm, you need to look at the zone number. Your sensor will be programmed as three zones, for example: Zone 4: smoke loop, Zone 5: heat loop, Zone 6: freeze loop. If Zone 4 goes off in this example, that means the smoke detection loop initiated the alarm. (This is most common, as there are a lot of environmental effects to consider, as mentioned above.)

For clarification, were you cooking at the time of the alarm?

We were not cooking when it went off. All cooking had ceased about 15 minutes before the alarm sounded. How do I find out which zone was set off? History shows:

First Floor Smoke Detector Fire Alarm 7:00 pm, Sep-8-2014

Ah, my guess is that would be the smoke function. Do you have the device named differently for the three loops?

In in your web browser, select “Security” then “Sensors.” It will list out the zone number and sensor names. (This is also where you select sensors for activity monitoring.)

have them named First Floor Smoke Detector, First Floor Heat Detector, and First Floor Freeze Detector. Next ?? is how do i know which was tripped?

If programed as loop1 smoke, loop2 heat, loop3 freeze you would have gotten an alert. its also on the panel under system history

Do you have detector installed near sink, kitchen, bathroom, vent or vent return. Is there dust on detector?

When was the last time you tested it with smoke?

"We were not cooking when it went off. All cooking had ceased about 15 minutes before the alarm sounded. How do I find out which zone was set off? History shows:

First Floor Smoke Detector Fire Alarm 7:00 pm, Sep-8-2014"

I take it the detector is in or near the kitchen? Expect false alarms due to cooking/ovens/etc. I get one occassinally in mine too. It is not recommended to install detectors in kitchen areas for this very reason.

You may want to enable verification on this particular detector (which will reduce false alarms)

First floor smoke… The number to the left of the sensor name is the zone (

To locate it on panel, and add verication, do the following:

Access system configuration (logo>installer code> system configuration)
Use right arrow to find “First Floor Smoke Detector”
Down arrow
Change (09) 24-hour fire to (16) 24-hour fire with verification
Down arrow until you see summary screen
(Verify sensor is loop 1)
Panel reboots

It is not located in the kitchen. Layout is kitchen - dining room then hang a left at the living room and its at the base of the stairs. I’ll double check the history and get back.


If its within 10’ or so of kitchen in an open floor plan, its close enough to be triggered by the oven/stovetop, etc

I suggest you also get compressed air (for like a PC/keyboard), and remove all detectors from bases and blow them out. If you are not cleaning the detectors expect false alarms due to dust particles (if you think there isn’t dust, you would be wrong. Look at ceiling fan blades, and what comes up after you vacuum. And its not the heating vents you need worry about…AC vents could easily stir dust particles right into detector). Humidity is another potential issue.

Make sure compressed air is for electronics otherwise it may leave a residue, and you should also be testing regularly with compressed smoke (99% never properly test their smokes, and then device fails. Usually when a detector fails someone dies)

Also, you need to check for blinking yellow lights on detector

I’ll give the smoke a try. I still do not see how it would be caused by smoke since we stopped cooking at least 15 minutes before the alarm sounded.

Last update - it was the smoke detector that went off not the fire. I guess I can rest assured knowing it works, but I am going to follow up with some canned smoke as well. Any suggestions on how to avoid false alarms while cooking?


Cooking is always problematic for smoke detection. Readjusting placement of the smoke detector is one solution. However, as was pointed out earlier, changing the zone type to fire with verification will cut down on false alarms, as it then must have a sustained amount of smoke to set the detector off twice in succession or for a solid 30 seconds (which amounts to roughly seven or eight audible cadences from the detector.)