Systems do not state that there is an alarm for no reason. Something happened. The state would not have changed to cause the alarm and then revert back to clear unless something happened. This will help you to understand what can cause an alarm and how to prevent/reduce these alarms from happening.
Sometimes we don’t see or understand why an alarm happened but something did happen. Aside from someone actually trying to open a door or windows, or successfully doing so when the system is armed, these are the other the most common reasons for your alarm:
The door or window is not properly aligned
The door or window is not properly secured
The sensor and magnet are not properly aligned
The magnet is missing
The sensor and/or magnet have been painted
A significant change in humidity and/or temperature
Gusts of wind or something hitting the door or window
Construction/work on your home-related issues
There are other reasons, these are the most common.
The state of a zone or device can vary by the system but generally is either normal, in alarm, or in trouble.
When a door or window is closed, the contact on it is generally in a normal state (closed). The magnet is aligned against a door/window sensor in most cases. If you have an internal contact it may have a push switch instead which can be of one of two types, a roller or a plunger. They both work the same way, much like a doorbell button or a light switch.
When a door or window is opened, the state will change to open. If the change happens when it is monitored for a change (i.e. armed), this state change will result in an alarm state and will be noted on the system panel(s) and sound locally. If the system is central station monitored, a signal will be sent to the central station.
A trouble condition may be noted when a sensor or magnet is failing. It could be a wiring issue, or if wireless, related to a device failure or simply a low battery condition.
For a door or window contact to work reliably and give you many years of protection will depend on many things:
Your doors and windows MUST be properly aligned and square. These conditions can/will happen over time. You should either check yourself or have someone check them regularly (We recommend spring and fall) to see if there are issues that need to be addressed. In addition to conditions changing over time, season changes happen as a result of temperature and other conditions, doors and windows can/will experience expansion and/or contraction. This can result in alarms happening due to being at or near the specifications of the contact/magnet such as the gap, range, or sensitivity. A properly aligned and secured door or window with a properly aligned contact/magnet will not have these issues.
If your doors or windows have latches or other mechanisms to make them be secured properly, their use is vital. Failure to do so makes them more prone to alignment issues and alarms as a gust of wind or a bird hitting the door or window, even someone knocking can cause an alarm.
Over time homes settle and conditions described here can happen that didn’t exist before. Work being performed in the home can also result in issues. We have seen instances where a contractor lost, broke, or damaged a contact or magnet. They may also have had one come loose or have to be put back on and alignment is vital. Another thing that can happen is that the wrong door or window is reinstalled and so the alignment of the contact and magnet are not correct. Equally important to alignment is the gap (distance between the sensor and the magnet).
We have also seen contacts and magnets that have been painted. No components in your system is designed to be painted. They MUST not be painted for any reason.
When the contact was installed, it was aligned and if there was an issue with the alignment/squareness of a door or windows, it was probably mentioned. It is important that your doors and windows be maintained and if there are any issues that they are promptly addressed. If you are having work done to your home, it is important to let your alarm company know that! Plan ahead and keep them in the loop.