Three things stack up in Andover specifically. First, the age of the hardware: with a median build year around 1993, a lot of original torsion springs and early-generation openers are well past their rated cycle count. Second, the climate: this whole service area sits in a band the federal data marks as severely cold, and spring steel fatigues faster through repeated hard freezes and thaws than it does in a mild climate. Third, income and door size: Andover's median household income of $131,528 runs well above the broader service area's $112,220, and higher-income households in this market more often run double-wide doors with two springs carrying more total weight, so when one spring fails the other is close behind.
Andover is a smaller piece of a large territory. Across the roughly 291,693 households Plymouth Garage Door Pros' service area covers, Andover's 11,087 households see the same cold-climate stress on hardware, just concentrated in homes built in a narrower window than the area average.