Set Appliance State:

Mains Power Off
Gas On; Pilot On
Rotary Switch in DHW position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Turn off the gas supply and allow the pilot to extinguish.
A few seconds after the pilot is extinguished a click should be heard from the gas valve as the mag valve closes.