Set Appliance State:

Mains Power Off
Ensure appliance primary circuit temperature is below 40°C
Boiler DHW thermostat set to MAX (65°C)
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Turn on the warm start feature.
The warm start feature is designed to heat the boilers primary circuit to the temperature set on the boilers DHW thermostat. In this case 65°C.