Sentinel began life as a brand in 1988 with X100, X200, X300, X400 and X500. This range of boiler and central heating system treatment chemicals still form the basis of the range today and remain immensely popular.  They branched out into physical devices in 2006, and were recently acquired by Aalberts N.V.

Sentinel have a clear goal: to offer water treatment products and services that provide the best lifetime protection for heating and hot water systems