Set Appliance State:

Mains Power Off
Wait 20 seconds before reinstating mains supply
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to complete its self-check.
Does the boiler reset & show the boiler flow temperature?
Note:
1. If the boiler fault code changes from the original to a different fault code, then CLICK HERE.
2. If fault the code is a recurring issue, then choose "boiler does not reset - fault code remains the same" to investigate possible causes.