Martin Door has one of the best warranties in the business by far. Most door brands have a 5 year, 15 year, or maybe a lifetime warranty against rust through damage only. Their hardware items, including springs, are typically covered for only one (1) year*, martin is covered longer... much much longer.
5 Year - Lifetime
Although professional annual service is recommended to maintain your door, it is not required to validate the warranty.
*refer to manufacturers' written warranties for details and limitations.
Ask to see the Warranty Comparison Page during your free in-home estimate.