TfL is also step free at T2/T3. Useful when travelling alone and having to roll two luggages. Even when Piccadilly Line was operating, I once arrived at T2/T3 tube station, and found the lifts not working and it's impossible to manage both luggages using the escalators down to the platform. The attendant recommended to take TfL instead to Ealing Broadway (where Central Line originates) and from there, connect to Central Line for central London.

Note this option is more expensive, almost double the cost of a straight-through exclusively tube ride.