Set Appliance State:

Mains Power Off
Set Multimeter to DC Volts Set meter to measure DC Volts
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

This test must be carried out during the fan and pump purge period (while FH is displayed)
Measure the DC voltage between the orange wire (pin 4)
at the 4 wire fan connector and a suitable earth.
Expect approximately 7 vdc.