Check your terminal before departing; Terminals 2 and 3 share a station

https://telegra.ph/Bus-Routes-to-Heathrow-Airport-Local-Services-Night-Buses-and-Fares-08-17-2

Check your terminal before departing; Terminals 2 and 3 share a station, while Terminals 4 and 5 have their own dedicated rail stops on the tube and Elizabeth line.