Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Selector switch to DHW position
CH temperature selector to minimum
DHW Preheat selector to OFF position
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow fan to run and burner to ignite.
With a flow rate of 9.8 litres/minute at the tap is there a temperature rise of 35°C and is operation satisfactory?