The Baxi control knob is a component located on the front of the appliance, allowing manual control of certain operational aspects. This can include adjusting temperature or changing the current function, such as enabling hot water generation independently of central heating. This part is a spare part and must be fitted by a certified Gas Safe engineer. Orders received before 4 pm are usually dispatched for the next business day. This control knob kit is suitable for Baxi NEW Platinum 24HE, 28HE, 33HE, and 40HE boilers. Product type: HARDWARE HANDLE. Manufacturer: BAXI.