self bleeding radiator valve Radiator valves are used to regulate the flow of hot water or steam in a heating system. There are two main types of radiator valves: thermostatic and manual. Manual radiator valves must be turned on and off by hand, while thermostatic radiator valves turn on and off automatically to maintain a set temperature. Self bleeding radiator valves are a type of manual valve that is used to remove air from the heating system. self bleed radiator valve