Using system hot water (❯60 °C), Horne’s patented ILTDU delivers targeted thermal disinfection at the water system periphery, where potable water meets a non-sterile (ward) environment. Combined with elevated velocity flushing, which mechanically shears and removes excess bulk biofilm, it addresses both established pipework biofilm, and contamination driven by retrograde ingress. This approach avoids selective pressures associated with chemical dosing, supporting control of Pseudomonas aeruginosa, NTM and other waterborne organisms while protecting system integrity, water quality and lowering environmental impact.