Graeme, the Code of Practice defines fixed equipment as "Equipment designed to be fastened to a support or otherwise secured in a specific location."
In section 5.5 it gives examples: central heating boiler, hand drier, fixed air conditioning unit, bathroom heater, electric towel rail, immersion heater, luminaire & water boiler and explains that fixed equipment can also be moveable or portable (or handheld) when connected to the fixed installation via a fused connection unit for security purposes, common in areas used by the public, e.g. hotels & changing rooms. So appliances such as hair driers, kettles, mini bars, lamps & clock radios.
So, in my view any appliance that is permanently connected to the fixed installation is tested as a Fixed Appliance, with the necessary safe isolation process to access the fixed wiring connections, but the frequency of inspection and test needs to take account of the fact that the appliance itself could be moveable, portable or hand-held.