1.   But recently he learned from a plumber that the chips were from a defective plastic tube in his water heater.

2.   He learned from a plumber that the chips were from a defective plastic tube in his water heater.

3.   In addition, plastic chips from the defective tubes clogged pipes, faucets and appliances.

4.   Since then, other newspapers and TV stations across the country have printed or aired stories about the defective tubes.

5.   The defective tubes were made by Perfection Corp., which then sold them to the water heater manufacturers.

6.   The letter said millions of water heaters were likely to fail because of the defective tubes.

7.   To cope with defective tubes, technicians can install plugs or insert liners inside them to cover the defective portion.