The 3 day London travel pass

London travel passes only work on the Piccadilly Line Underground train in from Heathrow to central London, which is often a very slow route unless your final destination is on that line. If you go in by Heathrow Connect you will need to buy an ordinary rail ticket at the airport station and then a travel pass from the Underground ticket office at Paddington station, where it arrives.

You cant use a travelcard on the heathrow connect... nor the express. They are run by private companies.You can buy the tickets at the station. I bought mine at paddington about 20 minutes before my train. The Heathrow Connect trains usually leave from platform 12, but check to make sure.

Unless you're staying near Paddington, you won't save much time taking the Heathrow Connect. By the time you walk from the train station to the Underground station and take the Tube to your hotel, you will only save around 20 minutes on your total travel time.

If you're traveling alone, I suggest that you buy an Oyster Card at Heathrow, load about £20 on it, and use it as a pay-as-you-go card. Use it to take the Tube into London. The Oyster computer will automatically give you the best fare and you will never pay more than 50 pence less than the cost of a one-day travelcard for the zones in which you travel each day, no matter how many rides you take. You can top up the card as needed and you can get a refund on any unspent money--plus the £5 deposit--when you return to Heathrow.