transportation from Heathrow to London

I'd suggest that you just take the tube from London Heathrow to Russell Square. It is a straight ride on the Piccadilly line with no transfers. This will be the least expensive and will probably be just as quick as the other options. If you take the train to Paddington, then your options are to switch to a taxi or take the tube from Paddington. You'd have to transfer twice (once at Paddington to get to the Hammersmith and City or Circle line and once at Kings Cross to the Piccadilly line), so I wouldn't recommend that.

I second Laura's suggestion to take the Piccadilly Line all the way from Heathrow to the Russell Square stop. My London Tube app estimates the journey at 47 minutes. If you take the Heathrow Express or Heathrow Connect to Paddington, you would then have to struggle with your baggage to get to Russell Square inside the Underground on 2 Tube lines. You'll be a wreck at the end. The only downside of taking the Piccadilly Line all the way is the many stops, which gets a littler tedious when you're weary after a long flight. But I've done it many times and now only opt for the Heathrow Express when I'm in a hurry to get into town as quickly as possible.

There is a direct bus route from Paddington to Russell Square (7) but it takes over half an hour. The quickest route by underground is Bakerloo to Piccadilly Circus, thence by Piccadilly Line, but the transfer is not step free - and as others have said, you can take the Piccadilly all the way from Heathrow. There has been long term lift refurbishment - one at a time which TfL give warnings about. Two should still be working but makes things crowded at peak time.

Thanks, everyone, for all the helpful information. I had researched the different ways of transportation, but it's nice to hear from those of you who have firsthand experience with them.

Is there an app or website where you can look up the best tube route between places? Like Patricia, I just assumed we would take the Heathrow Express to Paddington, and then find a way from there to our hotel's tube stop (which is Gloucester Road).
The more direct route that you guys have recommended to Patricia sounds much simpler. I just wondered how an outsider could discover something like that?

The old-fashioned way of getting around on the Underground is to use a map of the system. Maps are free and available at any Tube (Underground) station. You can also find maps in guidebooks and on the internet. Maps are posted on the walls within the entrances and exits to the Underground and also on the inside walls of the trains.

There are several available apps for the London Underground. I love a great free app called 'Tube Map' by mxData. It has a route planner by which you plug in a starting station and ending station and it tells you the best route. If you turn on the 'Smart Routing' feature, it factors in any problems, delays, engineering works, etc. that are occurring throughout the system that would impact your journey and suggests a route to avoid them. It also contains a Tube map that you can zoom in on (I find it difficult to read the tiny print on paper maps). mxData also makes an excellent free app called 'Bus London'. Another that a fellow poster here on the Helpline uses is called 'City Mapper'. I'm currently trying it out as well. Search the App Store for 'London Tube' and you'll get many results.

Ooops... Meant to say... You can also use the Journey Planner at the Transport for London website: http://journeyplanner.tfl.gov.uk/

For those reading this who do not like being underground ( like us): the Heathrow Express becomes more cost-effective if there are two or more traveling together. Two can get a DDuo Saver ticket if they are traveling into London and then back to Heathrow later. This works for us, as we generally build in an overnight or more in London on our way to or from the Continent. Then we either stay at a hotel near Paddington, or take a cab to our hotel. Then we stay above ground and get to enjoy the sights.

Nancy, I highly recommend that you take the tube directly from Heathrow to Gloucester Road. It is the quickest way. It takes less than 40 minutes on the Piccadilly line with no changes. There are some steps from the platform up to the elevator, but other than that it is quite simple. If you take the Heathrow Express, it will take you longer to get to Gloucester Road. If you take the Heathrow Express, you will then either need to transfer to a taxi or to the tube (circle line). If you need step-free transportation, then choose the Heathrow Express plus taxi. The transfer from the Heathrow Express to the circle line is not very pleasant and there are more steps from the circle line platform to the exit at Gloucester Road. I often stay at Gloucester Road and I lived in a flat near there for several months. I've timed it. The tube is faster, as well as much cheaper. For checking routes, you can go to tfl.gov.uk and enter your details in the journey planner.

Thanks, Laura. The Piccadilly Line sounds much better when we are arriving with (too many) suitcases. Glad to know that convenient route exists. I'll look into your list of apps and sources, Rose. Today we did a Facetime call with our son who moved to London 9 mo ago and he mentioned the Citymapper app. I've already installed that one. We'll be staying 9 days in London (minus a Tues-Wed trip to Bath), so we'll have a chance (and need) to get familiar with public transportation.
BTW, after the 9 days in London, we'll spend 2 nights in York then 3 in Edinburgh (during Festival), then another 3 in London (Bayswater), then home.

Nancy, your trip sounds great! You'll catch on to using the Tube really quickly. The great benefit of the apps, as I'm sure your son has figured out, is that they are able to factor into the Journey Planner any disruptions throughout the system and suggest a route to get you around it when need be. Have a wonderful time!