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)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Reset appliance if required (press and hold power button for 4 seconds then release).
Test 1:
Measure the DC voltage between pin 14 on connector X2
and an earth (use the copper pipe to the gas valve as earth)
before the pump begins to run for the self-check and make
a note of the reading (a system pressure of 1.2 bar will give
an initial voltage of approximately 1.8 Vdc).
Test 2:
Monitor the voltage when the pump runs, there should be an
increase of approximately 0.3 Vdc from the original reading
measured when the pump runs.
Is there an increase in voltage when the
pump is running as described above?
Test 1:
Measure the DC voltage between pin 14 on connector X2
and an earth (use the copper pipe to the gas valve as earth)
before the pump begins to run for the self-check and make
a note of the reading (a system pressure of 1.2 bar will give
an initial voltage of approximately 1.8 Vdc).
Test 2:
Monitor the voltage when the pump runs, there should be an
increase of approximately 0.3 Vdc from the original reading
measured when the pump runs.
Is there an increase in voltage when the
pump is running as described above?
Isolate as per TOPs P4
and refit as necessary