Troubleshooting Common Door & Window (contact) Sensor Issues

Common Terms

Sensor (Contact Sensor)

Device on a door or window reporting open/closed status to the panel.

Magnet (Strike)

Small piece that aligns with the sensor to register “closed.”

Tamper Switch (Cover Switch)

Internal switch that triggers if the sensor housing is removed.

Battery (Cell)

Power source inside the sensor (type varies by model—check your manual).

Bypass (Exclude)

Manual disabling of a sensor so it won’t trigger alarms.

Navigation Tips

• Qolsys IQ4/IQ2 (touchscreen): Swipe down from top or tap the ⚙️ icon, then choose Settings or Devices.
• 2GIG GC2/GC3 (keypad): Press the Menu or * key, enter your master code, then go to System Configuration > Zones.
• Under Devices or Zones, select your contact sensor to view status or perform actions (replace battery, clear tamper, etc.).
• Enter your master or installer code when prompted to access advanced settings.

Alarm Triggered

If your sensor causes an unexpected alarm:

1. Verify no one opened the door/window.
2. Open the sensor housing; align the magnet within ¼ inch of the sensor body.
3. Remove vibration or draft sources (fans, winds, heavy traffic).
4. On your panel:
   • Qolsys: Tap Security > Reset.
   • 2GIG: Press Off > Reset.
5. Test by opening/closing the door again.

Low Battery Warning

Your panel shows a low battery alert when sensor power is low. To replace:

1. Remove the sensor from its mount (slide or unclip).
2. Open the housing to access the battery.
3. Replace with the correct type (CR2032, CR123A, etc.), matching polarity.
4. Snap the housing closed until it clicks.
5. On your panel:
   • Qolsys: Go to Devices > select the sensor > verify alert cleared.
   • 2GIG: Go to Zones > select the zone > verify status.

Sensor Incorrectly Showing Open

If a sensor is showing open when the door or window is closed:

1. Check to ensure both the sensor and magnet are present on the door or window (you should see 2 white boxes, one bigger than the other). If a piece is missing, it may have fallen or been removed.
2. If both pieces are present, ensure they are within 1/4" of each-other when the door or window is closed.
3. If both pieces are present and the spacing is correct, ensure the alignment marker on the sensor is facing the magnet. The sensor is the bigger of the 2 pieces, and there will be an arrow or line on one of the sides to indicate which side needs to face the magnet.

Sensor Tamper Warning

Displayed when the cover switch is triggered:

1. Press the cover firmly until it snaps flush.
2. Inspect for cracks—replace cover if damaged.
3. Clear the alert:
   • Qolsys: Tap Alerts > Clear All.
   • 2GIG: Tap Trouble icon > find “Tamper” > press OK.

Sensor Loss of Supervision/Malfunction

The sensor is unable to report back to the system, usually due to a dead battery. To replace the battery:

1. Remove the sensor from its mount (slide or unclip).
2. Open the housing to access the battery.
3. Replace with the correct type (CR2032, CR123A, etc.), matching polarity.
4. Snap the housing closed until it clicks.
5. On your panel:
   • Qolsys: Go to Devices > select the sensor > verify alert cleared.
   • 2GIG: Go to Zones > select the zone > verify status.

Sensor Bypassed

A bypassed sensor is ignored by the system. To re-enable:

1. Disarm your system.
2. Open bypass settings:
   • Qolsys: Tap Security > Bypassed Devices.
   • 2GIG: Tap Menu > Bypassed Sensors.
3. Select the sensor > tap Un-bypass or toggle off.
4. Re-arm and test the sensor by opening/closing the door.

Tamper Events Disabled

If you’re not seeing tamper alerts, turn them back on:

1. Open sensor settings:
   • Qolsys: Tap Settings > Sensor Settings.
   • 2GIG: Press Menu > System Configuration > Zones > select zone > Options.
2. Toggle Tamper Alerts to On.
3. Ensure sensor housing is firmly mounted so the tamper switch engages.
4. Exit to save.

Additional Support

If your sensor still misbehaves, our Brinks Home™ Support team is here to help. Call 469-391-4024 or visit our Help Center.

Your home’s security is our priority—let us guide you every step of the way!