Set Appliance State:

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

Observation:

Carry out a combustion test using a suitable flue gas analyser, there is a test point at the top right of the appliance if the flue is not easily accessible.
Refer to TOPs A1 service & interim policies for more information.
Note:
Manufacturer instructions do not give any specific readings for this appliance.
This does not replace TOPs A1 interim & servicing policies.
Ensure all relevant safety checks are carried out.