Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to DC Volts Set meter to measure DC Volts
Gain access to display PCB
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the DC voltage between pin 4 (yellow) and pin 5 (green) at connector X7 on the display PCB.
Voltages depend on system pressure (refer to the manual pressure gauge) and should conform approximately to the table below:
Pressure (bar)DC Volts
0.50.6
1 0.9
1.51.1
21.4
2.51.6