The Sime part is located in the control knob section of the appliance. The control knob resides on one of the spindles located on the front of the appliance and allows the user to manually control certain aspects of the appliance's functionality. Some boilers allow you to change the temperature, and some even allow you to change the current function. This means the user can have the boiler provide hot water without the central heating being turned on and vice versa.

Brand Name	Sime