Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Disconnect pump speed control at the pump and make safe
Gain access to PCB (use insulation mat as necessary)
Gain access to PCB (use insulation mat as necessary)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
As pump is running during the boiler self check measure the DC voltage
between pin 2 (yellow) and pin 3 (black) at X13 on the PCB.
Voltage should be below 1V DC.
Once pump stops running voltage should change to approximately 4.5V DC.
between pin 2 (yellow) and pin 3 (black) at X13 on the PCB.
Voltage should be below 1V DC.
Once pump stops running voltage should change to approximately 4.5V DC.
Isolate as per TOPs P4
and refit as necessary