Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to DC Volts Set meter to measure DC Volts
DHW Demand
Gain access to PCB (use Insulation Mat as required)
DHW Selector to Max
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Press reset to cancel purge cycle countdown.
Measure the voltage across connections 3 (blue) and 6 (orange).
Allow burner to ignite and establish, voltage should then
increase to approximately 13 volts DC.