A dip tube is an internal pipe inside water heater tanks that directs cold incoming water to the bottom of the tank, ensuring efficient heating and preventing mixing of hot and cold water. This component is essential for proper water heater operation and stratification within the tank.
Design and Function
The dip tube extends from the cold water inlet near the tank top down to near the tank bottom, typically within 6-12 inches of the lowest point. This design forces incoming cold water downward where it can be efficiently heated, while hot water draws from the top outlet. Without proper dip tube function, cold water mixes with heated water, reducing usable hot water volume.
Common Failure Issues
Dip tubes can deteriorate from chlorine exposure, bacterial corrosion, or manufacturing defects, disintegrating into plastic particles that clog aerators and fixtures. Major recalls have addressed dip tube failures in specific heater models manufactured between 1993-2007.
Signs of Failure
Reduced hot water volume, water that cools quickly, or particles in hot water indicate potential dip tube failure. Replacement typically requires tank draining and 1-2 hours professional service. This relatively inexpensive repair ($150-300) prevents more serious tank issues.