Rheem Boiling / Kettling in Heat Exchanger

Heater makes loud banging, popping, or rumbling noises during operation.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Heavy scale buildup on heat exchanger tubes, low water flow, air pockets in heater, misadjusted bypass.

Safety First: Turn off power and gas. Allow the heater to cool completely before touching plumbing.

Check and improve flow: Clean the filter, ensure the pump is at the proper speed, and verify all valves to and from the heater are fully open.
Bleed air: If the system has air bleeders, open them to release trapped air. Ensure the pump is fully primed.
Inspect bypass settings: Adjust internal/external bypass according to Rheem instructions to ensure sufficient flow through the exchanger.
Schedule descaling: Persistent kettling usually indicates scale buildup. Have a professional chemically descale or, if necessary, replace the heat exchanger.

Hard 4/5

Heat Exchanger

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