Glow-worm Ultimate 3 combi offers both high DHW flow rates and flexible flue options. The high performance model also features a modulating Grundfos pump for reduced energy use a manual pressure gauge for easy installation and a modern, bright, LCD display with a simple to use interface. Designed using an automotive grade, aluminium heat exchanger and the Ultimate 3 offers proven reliability and performance whilst being light to install and also easy to maintain.