Apparatus and method for sensing ice thickness and detecting failure modes of an ice maker

An ice maker for forming ice using a refrigerant capable of transitioning between liquid and gaseous states, the ice maker comprising:

• (i) a refrigeration system comprising a compressor, a condenser, a thermal expansion device, an evaporator assembly, a freeze plate thermally coupled to the evaporator assembly, and a hot gas valve;
• (ii) a water system comprising a water pump, a water distribution tube, a purge valve, a water inlet valve, and a sump located below the freeze plate adapted to hold water;
• and
• (iii) a control system comprising:
• (a) an air fitting disposed in the sump defining a chamber in which air may be trapped and wherein the air fitting comprises one or more openings through which water in the sump is in fluid communication with the air in the chamber;
• (b) a pneumatic tube having a proximal end and a distal end, wherein the distal end is connected to and in fluid communication with the air fitting;
• and
• (c) a controller comprising a processor and an air pressure sensor, wherein the proximal end of the pneumatic tube is connected to and in fluid communication with the air pressure sensor and wherein the air pressure sensor is adapted to sense an air pressure from the water in the sump compressing the air in the chamber of the air fitting, wherein the sensed air pressure corresponds to a water level in the sump and wherein the controller is adapted to control the operation of the refrigeration system and the operation of the water system based upon the water level in the sump and to detect one or more failure modes of the water system based upon the water level in the sump.