Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Gain access to PCB (use Insulation Mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Test 1: Permanent Voltage
Measure the voltage between connector X501 to a suitable earth point.
Voltage should be approximately 73V AC.
Test 2: Voltage Drop on Ignition
Apply DHW demand
Continue to measure the voltage between connector X501 to a suitable earth point.
As the burner ignites the voltage should drop to approximately 60V AC or lower.
Measure the voltage between connector X501 to a suitable earth point.
Voltage should be approximately 73V AC.
Test 2: Voltage Drop on Ignition
Apply DHW demand
Continue to measure the voltage between connector X501 to a suitable earth point.
As the burner ignites the voltage should drop to approximately 60V AC or lower.
