Here's the honest limitation: a spring repair is only worth doing on its own when the rest of the door is sound. On a Manchester house built in the early '90s, that's usually the case - the track, rollers, and panel are the original age, and a spring swap gets the door back to full working order without touching anything else. Where it goes sideways is when the spring broke because something else was already dragging on the system: a bent track, a cable that's frayed from rubbing against a misaligned roller, or a panel that's taken a hit and is pulling the door out of square. In those cases, replacing just the spring buys you a week or two before the real problem breaks it again. Median household income in Manchester runs $100,222, well above the $80,694 median across the wider service area, and newer doors here tend to be heavier, insulated, double-wide units - which means a spring sized wrong for that extra weight fails fast, sometimes within the first few cycles. We'd rather tell you that up front than replace a spring twice.