Patent US 6,133,555

A control system includes a variety of structures including a steam table having a reservoir with heating elements, a water level temperature probe, a safety lower temperature probe, upper overflow probes for use in filling, lower safety probes, and normal water level probes; a thermal cabinet, ice machine and other thermal devices. The controller utilizes at least one of relay shaking, probe movement checking, probe feedback checking, disappearing equipment, water working system, air flow factoring, best verifiable logic, pulse cooling, AC energy sensor analysis, cooling potential sensor analysis and pulse heating to keep the heating elements at a more even temperature during the heating process and reduce extreme thermal cycling. In addition, the system can locate intermittent problems and display the problems to workers or management, or to a central controller to initiate action in advance to repair the problem before it causes a breakdown in the equipment.