One of the earliest BC preachers, his origins and date of birth are unknown. One account says that he came from the St. Neot area near Liskeard and had been turned out of his farm by a landlord unsympathetic to Methodism. (This was the area in which William O'Bryan had established his second 'private venture' before turning it over to the Wesleyans.) His arrival in the Week St. Mary-Shebbear area in 1816 was greeted by O'Bryan as a timely answer to prayer and he began his ministry about Christmas that year. It was he who suggested that the work in the north Tamar area might be extended to St. Neot and James Thorne initiated this in 1817. The St. Neot Circuit became the mother circuit of most of the BC work in east, south-central and south-east Cornwall.
Warne was one of four probationers present at the first BC Conference in 1819 and admitted into full connexion the following year. He spent at least five years in the circuits that arose from the absorption of John Boyle's societies west of Truro. In 1826 he was appointed Book Steward. When the first Financial Committee was appointed in 1827, at least in part to curb O'Bryan's extravagances, Warne was on it. But for much of his time as a preacher he was unwell and he died on 7 July 1828, leaving a widow and seven children. Edmund Warne, BC minister 1846-1853, was probably one of his sons.