Set Appliance State:

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

Observation:

Note: If boiler is stuck in a fault it will not be possible to access these settings. Use FAULT CODE DIAGNOSTICS.
Before continuing fault finding ensure CH is turned on and set to maximum (82°C)
Failure to set CH temperature may result in incorrect diagnosis.