Water Heaters · System Components

Expansion Tank

A small tank connected to the water heater system that accommodates thermal expansion of heated water, protecting the system from pressure damage.

Common uses

Accommodating thermal expansion, protecting against pressure surges

Common symptoms

• High water pressure
• Relief valve discharge
• Pipe stress

Common repairs

• Tank replacement
• Pressure adjustment
• Air charge service

Related terms

• Pressure Tank

Related diagrams