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 demand is present
Ensure No demand is present
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Cancel boiler purge / self-check (reset) if required.
Test 1. Wait 20 seconds then measure for DC voltage across pins 1 through 6 of connector X14 to a suitable earth connection.
Expected voltage approx 28 Vdc present on all pins, if voltages are not as expected then choose that option from below.
Test 2. Place boiler into st/by mode, wait 10 seconds then exit st/by, during initial 15 seconds, measure for dc voltage across pin 3 of connector X14 & a suitable earth connection.
Voltage should fluctuate during the initial 15 seconds then return to approx 28Vdc, (Note. Repeat as required until test complete).
Test 3. Repeat test 2 for pins 4, 5 & 6.
Test 1. Wait 20 seconds then measure for DC voltage across pins 1 through 6 of connector X14 to a suitable earth connection.
Expected voltage approx 28 Vdc present on all pins, if voltages are not as expected then choose that option from below.
Test 2. Place boiler into st/by mode, wait 10 seconds then exit st/by, during initial 15 seconds, measure for dc voltage across pin 3 of connector X14 & a suitable earth connection.
Voltage should fluctuate during the initial 15 seconds then return to approx 28Vdc, (Note. Repeat as required until test complete).
Test 3. Repeat test 2 for pins 4, 5 & 6.
