There's no security system so durable that it can go without regular maintenance and inspections. Have yours checked out once a year. Get a professional in to check it out. Many different things can make problems for your security system. If you don't see the problem, you may remain unaware of it.
If you've just gotten a home, replace every lock. Regardless of how trustworthy you consider the last owners to be, neither you nor they can be sure that there aren't others out there with keys to those locks. Besides, other tenants or owners might have copies of the key if the previous owners did not change the locks.
Shut off phone ringers inside the home if you're going to be gone