The Potterton control knob is located on one of the spindles on the front of the appliance and allows the user to manually control certain aspects of the appliance's functionality. Some boilers allow the user to change the temperature and even the current function. This means that the user can have the boiler produce hot water without turning on the central heating and vice versa.
Fits a number of Potterton appliances
Technical specification
TypeControl KnobToilet Cistern CapacityFTW--Supplier Part Number249119Brand NamePotterton