Originally Posted by
mickeypops
THe following buses, from stands 18, 19 and 20 (which are all together) all stop outside the LHR Marriott. You shouldn't wait more than a few minutes.
105,111,140,285,555,556,557
You'll pass the Renaissance on your right, then a McDonald's on the left, and it's the bus stop after that.
To return to the airport from the Marriott, head left out of the hotel, cross the road at the junction (about 100 yards) to the bus stop, and the same list of buses will return you to the LHR central bus station. I think the only bus that doesn't go the airport from here is the 222, so avoid that one
When getting on at Heathrow, it is sometimes necessary to tell the driver that you are going to Marriott / Sheraton / whatever so that he knows he plan to get off within the "free-flow" zone.
On the return all of the buses at that stop (Harlington Corner) which go to Heathrow should be free and there is generally no need to announce your destination.
Similarly if you get on at the stop you got off on the way to the hotel, some of the buses (285, 555, 556, 557, and ???) will take you to Hatton Cross Tube Station for free.