Rattling or whistling noise from the lid during pressure cooking.

Safety first: Keep clear of steam vents.

• Observe valve: Watch the steam release valve during operation. Slight hissing is normal, but loud rattling suggests looseness.
• Clean and reseat: After cooling, remove and clean the valve components. Reinstall firmly according to the manual.
• Replace seals: If the noise persists and seals appear worn, replace the valve seals or entire valve assembly.
• Adjust cooking: Reduce heat by selecting a lower pressure setting if available, and avoid overfilling with foamy foods.