The HydroFLOW HS38, first developed in the UK in 1992, represents the pinnacle of domestic limescale protection. With its innovative patented design and unique, electronic signal, the HS38 is suitable for installation in houses of up to four bedrooms, and can protect combination boilers as well as vented and unvented cylinders. The HS38 is designed to protect against hard limescale deposits in domestic pipelines and on heating elements and surfaces, to protect appliances such as dishwashers and washing machines, and to make limescale-stained taps, sinks and bathtubs easier to clean.