How do I commission the T80 Easi Fit for the first time?

Before switching on, set the power selector to 'COLD' and turn the temperature control fully clockwise to the 'MINIMUM' flow position, then attach the flexible hose but do NOT fit the showerhead. Turn on the water supply, then the electric supply, press the Start/Stop button, and slowly rotate the temperature control to MAXIMUM flow until a smooth stream of water is achieved — this flushes air and debris from the unit. Once flushing is complete, stop the shower and fit the showerhead before normal use. Failure to follow this procedure can cause the Pressure Relief Device (PRD) to operate and will invalidate the guarantee. (Page 15)