There are three different systems of indicator lights on our water dispensers. They are configured as follows : 1. For GWD200W, GWD230W/P, GWD330W/P Water Dispensers Amber – Hot water is ready to dispense Red – Heating Green/Amber – Green : Cooling / Amber : Cold water is ready to dispense. 2. For GWD770W/P, GWD880W/P, PWD885BLP, VWD886W Water Dispensers Digital temperature display, with thermometers. Numbers on the left indicate the temperature of the hot water, and the left thermometer moves when the machine is working to heat the water. Numbers on the right indicate the temperature of the cold water, and the right thermometer moves when the machine is cooling. 3. For rest of all Water Dispensers Green – System is receiving power.