The Glow-Worm 3bar Pressure Relief Valve 0020047005 is a crucial component for the Flexicom 30sx model residential boiler. Designed for indoor mounting, this valve ensures the safe and efficient operation of the heating system by relieving excess pressure. Manufactured by Glow-Worm, a trusted brand in the industry, this pressure relief valve is an essential part of maintaining and operating a reliable heating system in your home.