Sorry to bump but there's a new "Heathrow" hotel: ibis Styles London Heathrow East.

It's marked as "close to Hounslow West". The address is 366 Great West Road, TW50BD which puts it on the A4 and nowhere near an underground stop - it's almost a mile from Hounslow West and a mile from Osterley. (The map puts it much more centrally in Hounslow - actually inside the Treaty Centre. But that looks wrong).

Might be an easy bus into Heathrow though.