U04 warning; cooker beeps and cancels pressure program before heating.

Safety first: Ensure the cooker is cool and unplugged.

• Inspect gasket: Open the lid and check that the silicone or rubber gasket is present all around the inner lid. Look for gaps, twists, or sections that have popped out.
• Re-seat gasket: Remove the gasket completely, clean it with warm soapy water, rinse, dry, and then press it evenly back into the groove, ensuring it is not twisted.
• Check for wear: If the gasket is stiff, cracked, or flattened, replace it with a genuine Tiger gasket for your model.
• Test with water: Add water to the pot, close the lid, and start a pressure program. If U04 persists, the gasket sensor or lid detection may be faulty.