Set Appliance State:

Mains Power Off
CH Demand
Boiler CH temperature set to 50°C
(Press the radiator symbol then the - key to lower to 50)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to reach 50°C and the burner to shut down.
Increase the boiler CH temperature to Maximum - 80°C.
(Press the radiator symbol then the + key to raise the temperature to 80)
Observe the appliance it should re-fire after approximately 3 minutes.
Notes:
1. This setting is adjustable in the boiler parameters. If the boiler does not behave as described above it is advisable to check parameter 18.
2. The default setting is 3.
CLICK HERE for guidance on how check/adjust parameter 18.