Customers often call to report white particles clogging their shower heads, faucet aerators or floating in the bath tub or water glasses. These particles are often described as resembling eggshell fragments, scale or oatmeal. In many instances our laboratory has determined that these particles are plastic and that the source was limited to the hot water. It was further determined that the source of these particles is the failure of the plastic dip tube located inside the hot water heater in the home.
Most residential water heaters contain a "dip tube" that is commonly made of plastic. The dip tube is basically an extension of the cold water inlet that extends nearly to the bottom of the tank and directs cold water to the bottom to be heated. From August 1993 through October 1996, a series of defective dip tubes was manufactured and sold to major manufacturers of water heaters. The defect causes the dip tubes to degrade and disintegrate within an average time of 3 to 5 years. The result is that particles of this disintegrated plastic are released into the home plumbing to clog fixtures and reduce water pressure. The particles are non toxic and do not make the water toxic.
To determine if the dip tube is the source of the problem, place some of the white particles in a clear glass of water and see if they float. Because the dip tubes are plastic, they should float.
Once a defective dip tube is confirmed, check the age and warranty period on your water heater. If the unit is less than 5 years old, it's likely still under warranty and the manufacturer should be willing to repair or replace it. Contact your plumber, building contractor, or the manufacturer to report the problem. You will need to have the manufacturer, model number and serial number ready when you call; other useful information might include the date of purchase or installation, and your warranty documents.