It was the last thing Bill Fone expected. On a weekend afternoon last December, the silver, flexible pipe connecting hot water from the wall to his powder room basin burst. His son was able to shut off the water at the main within 10 minutes, but by then more than $40,000 of damage had been done.

The Fones’ experience is part of an epidemic of failures among flexible pipes that are helping to push insurance costs higher, and have led at least one insurer to promise to reject claims if flexi hoses aren’t properly maintained.