Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Refit combustion cover if this has been removed
Place FGA probe in air inlet test point
(point 2 on diagram), ensure it is fitted
securely to prevent any release of flue gases
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary and allow the boiler to complete its self check.
Set the boiler into service mode by holding down the service mode button for approx. 5 seconds.
Set the boiler temperature control to MAX to set the boiler to maximum rate.
To exit service mode press the service mode button once.
Allow FGA readings to stabilise and check that:
  • O2 levels are equal or greater than 20.6%
  • CO2 levels are less than 0.2%