Set Appliance State:

Mains Power Off
CH Demand
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Set the boiler into service mode by holding the       button for approx. 5 seconds.
Switch to maximum rate by using the DHW up and down arrows.
Allow burner to ignite and establish.
Using a FGA check if any POC are leaking from the
appliance burner or flue seals (indicated by FGA
showing CO or CO2 when placed near the seals).
Also inspect visually for any signs of corrosion or staining.