Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Remove electrical connector to diverter valve and make safe
Ensure NO demands are present
Ensure NO demands are present
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Test 1. Measure for DC voltage across connector X2 pin 8 (red lead) and a suitable earth connection.
Reset appliance (press reset button for 2 seconds and release), as the boiler resets the DC voltage at connector X2 pin 8 (red lead) should be seen to fluctuate between 0 - 20 Vdc then return approximately to 0 Vdc.
Test 2. Measure for DC voltage across connector X2 pin 18 (purple lead) and a suitable earth connection.
Reset appliance (press reset button for 2 seconds and release), as the boiler resets the DC voltage at connector X2 pin 18 (purple lead) should be seen to fluctuate between 0 - 20 Vdc then return approximately to 0 Vdc.
Reset appliance (press reset button for 2 seconds and release), as the boiler resets the DC voltage at connector X2 pin 8 (red lead) should be seen to fluctuate between 0 - 20 Vdc then return approximately to 0 Vdc.
Test 2. Measure for DC voltage across connector X2 pin 18 (purple lead) and a suitable earth connection.
Reset appliance (press reset button for 2 seconds and release), as the boiler resets the DC voltage at connector X2 pin 18 (purple lead) should be seen to fluctuate between 0 - 20 Vdc then return approximately to 0 Vdc.
Isolate as per TOPs P4
and refit as necessary