1.   A second company was aware of the defective dip tubes.

2.   Gagnon found out he had a water heater with a defective dip tube.

3.   Plumbers would detect and fix the defective dip tubes when on service calls.

4.   Then she read about the defective dip tubes and called American Water Heater Group, the company that made her water heater.

5.   The water-heater companies and Perfection now concede that they underestimated the problem, although they still believe only a fraction of the defective dip tubes will fail.

6.   Two dozen class-action suits have been filed against the water heater manufacturers and Perfection Corp., which made the defective dip tubes manufacturers used.