Set Appliance State:

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

Observation:

Is the system pressure approximately 1 bar when cold?
If pressure is correct add a small amount of water to the system. Does the pressure increase?
Note:
If appliance is stuck in a fault code then press the reset button, the system pressure will be displayed for half a second before returning to the fault.