Set Appliance State:

Mains Power Off
DHW Demand
DHW Selector in Maximum (+) position
CH Selector in Minimum (-) position
ON/OFF Switch in ON position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Allow boiler to ignite and run
With a flow rate at the tap of approximately 11.5 litres/min (1 pint in approximately 3.7 seconds) is there a temperature rise of 40° C and is operation satisfactory?