Kingly Court, Carnaby St
Liverpool Street Station #1
Liverpool Street Station #2
Heart of Valentines Park, Redbridge
Bexleyheath town centre
North Acton station square
Windrush Square, Brixton
Ladywell Fields
Beckhenham Place Park
Horniman Museum and Gardens
Paddington Recreation Ground
Acton Park
Guy’s Hospital
St Thomas’ Hospital
Swiss Cottage Open Space
Camberwell Green
Nisbett Walk, Sidcup town centre
Natural History Museum
St Alban’s Street, St James’s
The London School of Economics and Political Science
So here we have the first puff piece I've seen about the new drinking fountains:
https://www.theguardian.com/uk-news/2018/aug/28/londons-new-drinking-fountains-a-splash-hit