Hi there! I recently signed up for service two months ago. I have an IQ2 panel and a Hardwire 16 to takeover the existing wiring in my home. All has been working well until the middle of the night last night when an alarm was triggered. The zone that was triggered has 4 windows and 1 door and was set with a delay turned on (although Alarm was set to stay/instant). After clearing the house and checking on the zone, nothing was opened and all windows were shut/locked. This part of the home is at a height that is not accessible from the ground, so I can’t believe any of the sensors were actually opened. I also checked the wiring at the Hardwire 16 for any loose connections (while holding the panel and in the sensor status menu) to see if anything was triggered while moving the wires - no issues observed. I also checked the event history for any other open/close events of this zone to see if it was potentially occurring without my knowledge during the day with the alarm off… No other events had been triggered. Needless to say, I am a bit baffled as to what could have caused this and would hate for it to occur again in the middle of the night…
Happy to help! Wired sensor inconsistencies can be annoying to troubleshoot, but in general if a wired zone opens when the sensors were not disturbed there are a few possible causes:
Loose wiring. Yes, that is a common cause and good to check for.
Sensor alignment. Sensors and magnets need to be aligned properly and proper distance in order to stay closed until the door/window is disturbed. Check all the sensors on that zone and make sure that the magnets are lined up properly and not too far away. Distance will depend on the sensor model, but check for any that appear to be a half-inch off or more or off-set.
Resistance. The sensor detection circuit determines if the sensor is open or closed by reading resistance value. Old wiring can have some wear and tear (corrosion, brittleness, etc.), and solid wire is particularly susceptible to weakening near the termination points where they are screwed down. Resistance can be affected due to wear and tear.
Also note that the Hardwire 16 registers the specific resistance of the zone when you learn it in, and then looks for deviation from that resistance value to determine activity on that zone.
Using a multimeter or ohmmeter, you can test the resistance of the sensor circuit between the two wires. If the resistance is higher than the resistor value, that might suggest corrosion or damage.
A good proactive measure is cutting and exposing fresh wire when working on taking over wired sensors, this ensures the wires are unlikely to be damaged or weak at or near the termination point. If you notice false alarms like this, I would suggest doing this at both the Hardwire 16 end and the sensors themselves.