Heatline Boilers Heatline is a trustworthy UK manufacturer of affordable, high quality domestic central heating solutions including high-efficiency condensing boilers and more, available from PlumbNation plumbing and heating supplies. Heatline’s 50 years of manufacturing experience has attained a solid reputation amongst installers who opt for Heatline products for their ease of use and comprehensive installation procedures. Heatline is part of Vaillant Group and all CaprizPlus boilers come with Vaillant's full after sales care service.