Set Appliance State:

Mains Power Off
Selector switch set to CH/DHW position
Ensure NO demands are present
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

When the power is switched on the boiler will carry out a self-check.
Monitor the pump operation.
The boiler should then enter stand-by mode.
Whenever power is reinstated the LED will flash red then orange
consecutively 8 times, once this cycle is complete the LED will
flash green thereafter once every 4 seconds to indicate stand-by mode.
If a FAULT CODE is displayed then you MUST choose that option below to avoid misdiagnosis.