I have a Glow -worm Ultimate 3 30C combi-boiler. In the eight years it has been in there has been four repairs carried out, two under warranty. It has failed two of it's last three services necessitating being 'made safe' - turned off awaiting repair. The last instance meaning we had no hot water or heating in early February. My communication with Glow-worm (Valiant) has been problematic. To my mind a poor product and poor customer service.