Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Disconnect electrical connector from the fan
assembly, position in a safe place
Ensure NO demand
assembly, position in a safe place
Ensure NO demand
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Click here for more information before carrying out this test.
Reset appliance press and hold reset button for 5 seconds, then release.
Preheat OFF (ECO button illuminated), this should be done A.S.A.P after reset has completed
to prevent the boiler attempting to run the fan. (pump should not be running if it is repeat the above)
Test 1:
Measure for AC Voltage across terminals 2 (Brown) and 4 (Yellow) of connector ST5 and
note the reading.
Test 2:
Turn Hot Water Tap On, DHW Temperature Control to MAX.
Measure for AC Voltage across terminals 2 (Brown) and 4 (Yellow) of connector ST5 again.
Expect an increase in voltage of approximately 1.3 VAC or greater from the original voltage
measured on the first test.
NOTE: If appliance lockout occurs (approx after 30 seconds) during test, reset appliance as required until test complete.
Reset appliance press and hold reset button for 5 seconds, then release.
Preheat OFF (ECO button illuminated), this should be done A.S.A.P after reset has completed
to prevent the boiler attempting to run the fan. (pump should not be running if it is repeat the above)
Test 1:
Measure for AC Voltage across terminals 2 (Brown) and 4 (Yellow) of connector ST5 and
note the reading.
Test 2:
Turn Hot Water Tap On, DHW Temperature Control to MAX.
Measure for AC Voltage across terminals 2 (Brown) and 4 (Yellow) of connector ST5 again.
Expect an increase in voltage of approximately 1.3 VAC or greater from the original voltage
measured on the first test.
NOTE: If appliance lockout occurs (approx after 30 seconds) during test, reset appliance as required until test complete.
Isolate as per TOPs P4
and refit as necessary