Coupler for use in liquid heater and liquid heater

摘要

A coupler for use in a liquid heater includes a male connector and a female socket connector. The male connector includes a connecting wall and an annular cylindrical wall formed around the connecting wall. The female socket connector comprises an end wall joined with the connecting wall of the male connector and a peripheral wall formed around the end wall and arranged perpendicularly to the end wall. The surface of the end wall joined with the connecting wall is gradually lowered from the center towards the periphery and is convex-hull shaped. The peripheral wall includes arced sections and gapped sections connected between two arced sections. When the male connector is coupled with the female socket connector, this allows the arced sections to be coupled with the annular cylindrical wall and forms no coupling between the gapped sections and the annular cylindrical wall.