Ways a vampire can dieEdit
Vampires can die in several ways, some more successful than others. In "Dark Knight: The Second Chapter", while battling in the warehouse, LaCroix lists some of the methods he believes will work when he says "With fire, a stake through the heart, the sun. All these will do it my friend--and one more. Decapitation." Some of these have been employed directly on camera in various episodes.
Exposure to sunlight. In "Last Act", Erica commits suicide by exposing herself to direct sunlight after dawn. The same holds true of the South American vampire, Angel, who walks into the sunlight after creating Vachon and the Inca. In the episode, "Can't Run, Can't Hide", the Vietnamese vampire, Tran committed suicide by sitting in the sunlight once his revenge was sated.
It is worth nothing that Nick regularly sees the dawn hours and frequently starts emitting smoke from his body when he exposes himself to even the direct dawn sunlight. Simply hiding from the sunlight during the daylight hours is enough to protect a vampire, as evidenced by his frequent use of the trunk of his caddy.
Staking. In "A More Permanent Hell", Nick stakes Spark successfully and in "Ashes to Ashes", the wounded Vachon is staked by Tracy Vetter at his request, though it is possible that Vachon would have died anyway.