It is possible for the lid to get stuck if the reactor has not been opened for an extended period of time or has been done up too tightly.

To remove a very tight lid ask someone to hold the reactor body while you carefully tap the lid around, on the corners, with a rubber faced hammer or mallet. Take care that you are trying to twist the lid in the correct direction.

To help prevent this happening again lubricate the o-ring with food grade silicone grease before replacing the lid. The lid only needs to be gently hand tightend.