Originally Posted by
motef
We got the shuttle bus from the AVIS station and went to T2 which we then planned to get on the Tube but the Piccadilly line was closed due to maintenance so we had to walk to the Elizabeth line
A service that's still attached to the terminals though and not that hard to reach.
Without dates, it's hard to be able to tell you when there will be tube line maintenance and therefore give details of alternative options. You can always check that on the TfL website before travel.