Diagnosis
The lid is locked because pressure is still trapped inside the cooking pot. The "button" you refer to (the lid lock) is a safety mechanism that physically prevents the lid from rotating and opening while the internal pressure is above a safe threshold. Forcing it could damage the locking mechanism or, more dangerously, cause a sudden, explosive release of steam and hot contents.
How to Fix It
- Turn off and unplug the appliance if it's electric, or move it off the heat if it's stovetop.
- Let it cool naturally. Do not attempt to quick-cool it by running cold water over the lid or placing it in the fridge, as this can warp components.
- Wait for the pressure indicator. The float valve (the small metal or plastic pin near the lid handle) must be fully down.
- Ensure all steam is released. Check that the quick release valve is in the "Seal" position and is not hissing. No steam should be coming from any valve or the lid seal.
- Once completely depressurized and cool, the lock button should disengage automatically when you press the lid handle release lever, allowing you to rotate and open the lid.
If That Didn't Work
If the unit is cool, depressurized, and the button remains stuck, food debris or hardened starch may be jamming the lock mechanism or the float valve. Ensure the pot is cool, then carefully clean around the float valve and the lid's inner rim with a damp cloth. For a stovetop model, you can also try gently tapping the lid lock button with the handle of a wooden spoon to free any minor obstruction.
Heads Up
Never submerge the entire lid or the electric base in water. If the lock mechanism is physically broken or the lid is damaged, discontinue use immediately, as the pressure cooker will not be safe to operate.