Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
CH Demand
Ensure all rads are turned on
Attach temperature clamp to flow pipe
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow appliance to run ignition sequence, after 5 attempts the appliance will go to ignition lockout.
Monitor the flow pipe temperature and when this reaches
approx. 40°C or below CLICK HERE
Note.
Pump will continue to run whilst appliance is in lockout.