Q: I'm not sure if the temperature gauge is working... why is it not showing any readings?

A: If your temperature gauge isn't showing any readings, it's very likely that the temperature of the liquid is falling somewhere outside of 58-88 degrees, so it can't read it.  (Typically, this happens when mixing the warm sweet tea and the liquid is still above 88 degrees) 

If the temp gauge is reading 2 or 3 colors, this means the actual exact temperature is lying somewhere in between the numbers on the gauge. Green indicates the correct temp. If green is not visible, the temperature will be midway between what is illuminated by tan and blue.