A surface treating appliance includes a surface treating head, a hose and a main body including a fan unit for generating a flow of fluid and a rotary changeover valve. The changeover valve includes a valve body having a first section for receiving fluid flow from the surface treating head, a second section for receiving fluid flow from the hose, and third section for conveying fluid flow towards the fan unit; and a valve member which is selectively moveable between a first position which connects the second section to the third section, and a second position which connects the first section to the third section. To minimize the number of components of the main body, the valve body forms part of a casing for the fan unit.