Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Selector switch set to CH/DHW position
Boiler CH thermostat set to MAX
Remove right hand side panel
Attach temperature clamp to flow pipe as indicated by the red arrow
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow the burner to ignite and heat up the system until MAX temperature is reached.
Monitor the appliance temperature.
Note:
To reduce the time for this test the heating load can be reduced
by turning off some radiators temporarily.