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 PCB (use Insulation Mat as required)
Remove the connector from the pressure sensor and make safe
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure for DC voltage across pin 39 of connector CN2 & and pin 4 of connector CN4.
Expected voltage approximately 5 Vdc.