Glow-worm 0020014161 automatic air vent

An automatic air vent designed for the pump section of Glow-worm Sustain, Ultrapower, Easicom, Energy, Flexicom, Miscellaneous, Ultimate 2, Ultracom, Energy 7, Essential, Home, Ultimate 3, Betacom, Envirosorb and Energy 2 boilers. A central heating safety device, the air vent releases built up air. As water flows through the system, a float opens or closes the vent depending on the water level. When the system is full the float is pushed to the top, closing the vent until the water level drops