Although it is widely believed that Bath has the only geothermally heated surface spring in Britain, this is not true. As well as Hotwells in Bristol (See Note), other warm springs known of before the pumping associated with recent spas and mining include: Taff's Well, near Cardiff (20oC./68oF.*); and Buxton (Camden* : Darbyshire). One Life of St. David suggests he was responsible for a "Hot Baths" spring at Glastonbury*, though this may be a confusion with Bath. Jones* gives two "Holy Wells" in Wales that steam in cold weather: Ffynnon Elan, near Gelli'r Pentref Dolwyddelan and Ffynnon Lygaid, Llanfynydd Bog, Carm., while also noting of the two Penegoes Wells, Montgomeryshire/Powys, that one is reputed warmer than other. There are, in addition, a number of sites known as "Hot/Warm Wells" that may or may not be warm, for example, Hotwells Spring, Little Newcastle*, and the village of Warmwell in Dorset, which may or may not** be is based around a, er, warm well.
Note: the English term "Walme" means to boil, in the sense of bubbling - while this was usually associated with heating, it was not necessarily so, so one has to be wary of descriptions of springs that "walme": for example, that for Newnham Regis in Camden* : Warwickshire.