Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Turn Hot Water Tap On
Gain access to PCB (use Insulation Mat as required)
Disconnect plug from fan and make safe
Disconnect plug from fan and make safe
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Test 1:
Measure the voltage between pin 2 of X3 on the PCB to a suitable earth point.
Voltage should be approximately 28V DC.
Test 2:
Measure the voltage between pin 4 of X3 on the PCB to a suitable earth point.
Voltage should be approximately 28V DC.
Note:
Appliance may enter lockout during test, reset as necessary until test is complete.
Measure the voltage between pin 2 of X3 on the PCB to a suitable earth point.
Voltage should be approximately 28V DC.
Test 2:
Measure the voltage between pin 4 of X3 on the PCB to a suitable earth point.
Voltage should be approximately 28V DC.
Note:
Appliance may enter lockout during test, reset as necessary until test is complete.
Isolate as per TOPs P4
and refit as necessary