Warner was educated at Harrow School and at Trinity College, Cambridge.
[2] He was ordained as a Church of England deacon in 1864 and as a priest two years later and served as curate at parishes in Devon until 1875.
[2] In 1875, Warner became headmaster of the Newton Abbot Proprietary college; one of his pupils there was the writer Arthur Quiller-Couch who wrote of him:[2] A tall sanguine man, in the middle years, but athletic yet, a rare runner between wickets; in school, and out of it, an organiser: a gentleman with every attribute of a good Head Master save a sense of justice, of which he had scarcely a glimmer, and being choleric, could be angriest when most unjust.Warner also taught Bertram Fletcher Robinson and Percy Fawcett who later befriended and influenced the author, Arthur Conan Doyle.
[3] From 1895 to his death in 1902 he returned to church work as rector of Alfold, Surrey.
[2] Warner's younger brother William was a much more successful cricketer at Cambridge University.