220-1102 Question 316
Single answerAlarm systemsA small medical office recently installed a smart alarm system that sends alerts to a mobile app. The office manager reports that the system randomly shows the front door as open after hours, which triggers repeated notifications and causes the monitoring service to call staff. When a technician checks on-site during the day, the door appears closed and locked, and the alert clears temporarily after reopening and shutting the door. Which action should the technician take FIRST to address the most likely cause of the false alarms?
- A
Inspect and realign the door contact sensor and magnet to ensure proper positioning when the door is closed
- B
Replace the office Wi-Fi router because delayed cloud communication is the most common reason for false door-open events
- C
Disable mobile notifications for the office manager until the vendor releases a firmware update
- D
Increase the alarm siren volume so staff can verify whether the door is actually open during an alert
Show answer and explanation
Correct answer: A
Explanation
The best first step is to check the physical door contact sensor and magnet. In alarm systems, false open/close events are commonly caused by misalignment, weak mounting, excessive gap distance, damaged contacts, or a shifting door frame. This is especially true when the problem temporarily clears after the door is opened and closed again. Standard troubleshooting best practice is to start with the simplest and most likely physical cause before replacing network equipment or assuming a software defect. Vendor installation guides for intrusion sensors typically specify correct alignment marks and maximum gap tolerances for magnetic contacts, and those specifications should be verified during troubleshooting.
- A. Correct.
This is the correct answer. Door and window alarms commonly use magnetic reed switches or similar contact sensors. If the magnet and sensor are misaligned, mounted too far apart, or slightly shifted due to door movement, expansion, or loose hardware, the system may intermittently interpret the door as open even when it is shut. Since the alert clears after the door is reopened and closed, a physical contact issue is the most likely cause, so inspection and realignment is the appropriate first troubleshooting step.
- B. Incorrect.
This is incorrect. Network problems can delay notifications or prevent remote status updates, but they do not usually cause the alarm panel itself to falsely detect a door as open. The symptom points to a bad or misaligned input from the door contact, not a router problem. This option reflects a common misconception that all smart alarm issues are primarily Wi-Fi-related.
- C. Incorrect.
This is incorrect. Disabling notifications only hides the symptom and does not address the underlying cause of the false alarm. A firmware issue is possible in some smart devices, but the repeated pattern tied to physically reopening and closing the door makes a contact alignment problem much more likely. Good troubleshooting practice is to verify the sensor hardware before escalating to software or vendor-level causes.
- D. Incorrect.
This is incorrect. Increasing the siren volume does not help diagnose why the system believes the door is open. It also introduces unnecessary disruption and does not fix sensor input problems. This option confuses alerting behavior with fault correction.