A.O. Smith water heater vibrates or makes banging noises in piping when heating

Safety: Secure ladders and work carefully around hot pipes.

• 1. Secure pipes: Add or tighten pipe clamps and supports near the heater and along accessible runs.
• 2. Install hammer arrestors: At problem fixtures (dishwasher, washing machine), install water hammer arrestors.
• 3. Add expansion tank: On closed systems, install a thermal expansion tank on the cold inlet to reduce pressure spikes.
• 4. Check pressure: Verify system pressure is within recommended limits (40–80 psi).