How to Fix / Troubleshooting

Safety first: Turn off power and gas. Allow heater to cool before touching plumbing.

Steps to address banging/popping noises:

Check water flow: Ensure all valves to/from the heater are fully open and the filter is clean. Increase pump speed if using a variable‑speed pump.
Bleed air: If the system has air relief valves, bleed trapped air from the filter and high points in the plumbing.
Assess for scale: Long‑term operation with hard water often leads to scale, causing localized boiling. Have a professional inspect and chemically descale the Raypak heat exchanger.
Monitor after cleaning: After restoring proper flow and descaling, noises should diminish. Persistent kettling may indicate internal damage requiring heat exchanger replacement.

Warning: Do not ignore severe banging; it can damage the heat exchanger and headers.

Heater makes loud banging or popping noises during operation.

Possible Causes