The young cleric Heimo entered the service of Duke Béla, the eldest son and heir of Andrew II of Hungary. He functioned as chancellor of Béla's ducal court in Slavonia in 1222. He was succeeded by Matthias Rátót in this capacity by 1224.
Heimo was elected Bishop of Vác in the second half of 1243 or early 1244, succeeding Stephen Báncsa. In 1244 or 1245, Béla IV entrusted Heimo and local ispán Henry Kőszegi to investigate and supervise previous royal land grants occurred in Vas County. In December 1252, Pope Innocent IV mandated Heimo and Zlaudus Ják to implement the papal command concerning the appointment of Stephen Báncsa as administrator of the Archdiocese of Esztergom. Heimo last appears in contemporary records in 1254, when Béla IV instructed him to assign the uninhabited royal land Kovácsi in Pest County to Egidius Kókai. Heimo was succeeded as bishop of Vác by Matthias in 1259 at the latest.