Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Gain access to PCB (use Insulation Mat as required)
Ensure NO demands present
Ensure NO demands present
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow self check to complete.
Test 1.
Measure for DC voltage between pin 3 (brown) on connector CN25 to a suitable earth point.
Expected voltage approx. 5.2 VDC
Test 2.
Turn hot water tap ON and repeat test 1.
Expected voltage approx. 0 VDC.
Test 1.
Measure for DC voltage between pin 3 (brown) on connector CN25 to a suitable earth point.
Expected voltage approx. 5.2 VDC
Test 2.
Turn hot water tap ON and repeat test 1.
Expected voltage approx. 0 VDC.
Isolate as per TOPs P4
and refit as necessary