My Drinking Water Lab has an old Castle 3020 Steam Sterilizer that I need to keep in service rather than replace due to budget concerns. Here is my issue: Yesterday a cycle did not complete and in order to relieve pressure after several hours I had to cut power to the unit and blow off the boiler. This morning I turned on the boiler and as the jacket began to fill it was making an extremely loud popping and clanking sound. In order to stop it I had to once again cut power and exhaust the boiler. It almost sounded like there was water in the jacket that has not exhausted. I do not know if that is the case and do not know how to clear the jacket of water if it is the case. Any guidance on what to do would be appreciated. Thanks!