A pressure-cooker lid that will not open may still be held by pressure. Do not force it, defeat the lock, or shake the cooker.
Releasing pressure. Turn off the heat and follow the release method in your model's manual. Wait for the pressure indicator to reach the safe position and for any other conditions specified by the manual; a fixed few minutes is not sufficient for every model or food. Quick release may be unsuitable for foods that foam or splatter.
Using water. Use cold-water cooling only on stovetop models whose manual explicitly allows it. Do not put an electric pressure cooker under running water or immerse it. Keep hands and face away from steam and do not manipulate valves outside the instructions.
If the lid remains stuck. If it will not open even after complete cooling and confirmation that no pressure remains, follow the manufacturer's service guidance rather than applying force. Maintain seals, valves, and locks only while the appliance is cool, replacing worn parts with model-appropriate replacements. Not all electric models release pressure automatically; the model's instructions govern.