Oso water heater making loud popping or kettling noises during heating.

Safety first: Isolate power and allow the cylinder to cool before draining or removing the element.

• Assess water hardness: If you are in a hard water area, scale is likely the cause of noise.
• Drain and inspect: Drain the cylinder to below the element, remove the element, and inspect for heavy scale deposits.
• Descale or replace: Carefully remove scale from the element or replace it if heavily coated or damaged. Vacuum or flush loose sediment from the cylinder bottom.
• Consider water treatment: Install a scale reducer or softener upstream of the Oso heater to reduce future buildup.
• Set appropriate temperature: Avoid unnecessarily high thermostat settings, which accelerate scale formation.