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)
No demand
No demand
| 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 across pins 1 to 6 of connector X3 and a suitable earth connection.
Expected voltage approx. 24 Vdc present on all pins, if voltages are not as expected then choose that option from below.
Test 2. Power off the boiler (see note), wait 10 seconds then reinstate the power, during initial 10 seconds of self-test, measure for dc voltage across pin 1 of connector X3 & a suitable earth connection.
Voltage should fluctuate during the initial 10 seconds then return to 24Vdc, (Note. Repeat as required until test complete).
Test 3. Repeat test 2 for pins 3,4 & 6.
Note. Power off boiler using the On/Off switch.
Test 1. Measure for DC voltage across pins 1 to 6 of connector X3 and a suitable earth connection.
Expected voltage approx. 24 Vdc present on all pins, if voltages are not as expected then choose that option from below.
Test 2. Power off the boiler (see note), wait 10 seconds then reinstate the power, during initial 10 seconds of self-test, measure for dc voltage across pin 1 of connector X3 & a suitable earth connection.
Voltage should fluctuate during the initial 10 seconds then return to 24Vdc, (Note. Repeat as required until test complete).
Test 3. Repeat test 2 for pins 3,4 & 6.
Note. Power off boiler using the On/Off switch.
