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Why Does My Burglar Alarm Keep Going Off?
A burglar alarm that keeps going off unexpectedly can be frustrating for homeowners, disruptive for businesses, and embarrassing if it happens in the middle of the night. While it may be tempting to ignore the problem or simply silence the alarm, repeated false alarms usually indicate that something within the system needs attention.
In this guide, we'll explain the most common reasons why burglar alarms go off unexpectedly, what you can do to resolve the issue, and when it's time to call a professional security engineer.
Common Reasons Your Burglar Alarm Keeps Going Off
There are several reasons why an intruder alarm may trigger without an attempted break-in. Some are simple to fix, while others require professional maintenance.
Low Backup Battery
One of the most common causes of alarm faults is a failing backup battery.
Over time, the rechargeable battery inside the control panel loses its ability to hold charge. When this happens, the system may display a warning message, emit regular beeps, or trigger false alarms.
Most alarm batteries last between three and five years, so regular servicing and timely replacement are essential.
Faulty Motion Sensors
Motion detectors can become less reliable as they age or if they become dirty.
Common causes include:
- Dust or spider webs covering the sensor
- Insects inside the detector
- Sensor misalignment
- Internal component failure
A faulty PIR (Passive Infrared) sensor may interpret environmental changes as movement, causing the alarm to activate unexpectedly.
Loose Door or Window Contacts
Magnetic contacts fitted to doors and windows can wear over time.
If a contact becomes loose or slightly misaligned, the system may think a door or window has been opened when it hasn't.
This is a common issue on older systems or doors that experience frequent use.
Power Supply Problems
Power cuts or electrical fluctuations can sometimes trigger alarm faults.
While your backup battery should keep the system running during a power outage, an ageing battery may fail to do so, resulting in warning beeps or false activations.
Incorrect User Settings
Sometimes the issue isn't hardware at all.
Problems can occur if:
- Entry or exit times are too short
- The system has been incorrectly programmed
- User codes have been changed
- Recently added devices haven't been configured properly
If you've recently had work carried out on your alarm, it's worth checking whether the settings need adjusting.
Environmental Factors
Modern alarm systems are sensitive enough to detect movement and environmental changes.
False alarms can sometimes be caused by:
- Strong sunlight shining directly onto sensors
- Rapid temperature changes
- Air conditioning or heating vents
- Pets moving through protected areas (if non-pet-friendly sensors are fitted)
Choosing the correct type of detector for each room helps minimise these issues.
Should You Ignore False Alarms?
No.
Even if the alarm eventually stops on its own, repeated false alarms usually indicate that part of the system isn't functioning correctly.
Ignoring the problem could eventually leave your property without reliable protection when you need it most.
Frequent false alarms can also cause neighbours to ignore future alarm activations, reducing the effectiveness of your security system.
When Should You Call a Professional?
You should arrange an inspection if:
- Your alarm keeps triggering without explanation
- The system displays fault codes
- The backup battery has reached the end of its lifespan
- The alarm sounds after every power cut
- Your system hasn't been serviced for several years
A qualified engineer can quickly identify the source of the problem, replace worn components and ensure your alarm is operating correctly.
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Can You Fix the Problem Yourself?
Some basic checks are safe to carry out, including:
- Looking for low battery warnings
- Checking whether doors and windows are fully closed
- Ensuring sensors aren't obstructed
- Cleaning dust from around detectors
- Replacing batteries in wireless sensors (where recommended by the manufacturer)
However, you should avoid opening the control panel or attempting to rewire components unless you're familiar with the system, as this may trigger additional faults or damage the equipment.
Preventing Future Alarm Problems
Regular maintenance is the best way to avoid unexpected alarm faults.
An annual service allows engineers to:
- Test the backup battery
- Inspect all detectors
- Check door and window contacts
- Verify sirens and sounders
- Update system settings if required
- Identify worn components before they fail
Routine servicing not only improves reliability but can also extend the life of your security system.
Need Help With a Faulty Burglar Alarm?
If your burglar alarm keeps going off unexpectedly, don't wait until the problem becomes more serious.
At Burgess Security, we provide professional alarm servicing, repairs and maintenance for domestic and commercial properties across the North West. Whether your system requires a replacement battery, fault diagnosis or a complete upgrade, our experienced engineers are here to help.
Contact Burgess Security today to arrange a service or discuss your alarm system with one of our specialists.
