Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Remove the Fan Connector from the fan assembly and make safe
Boiler Thermostat to MAX
CH Demand
On / Off switch OFF
Boiler Thermostat to MAX
CH Demand
On / Off switch OFF
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Observation:
Click here for more information before carrying out this test.
Place the black probe on the brown wire (N), the red probe
on the yellow wire (PWM) then turn the On / Off switch ON
while monitoring the AC Voltage.
Expect an initial voltage when the On / Off switch is first turned
on which then increases after approximately 6 seconds.
Note:
Repeat test from the beginning as necessary
until the result has been accurately determined.
Place the black probe on the brown wire (N), the red probe
on the yellow wire (PWM) then turn the On / Off switch ON
while monitoring the AC Voltage.
Expect an initial voltage when the On / Off switch is first turned
on which then increases after approximately 6 seconds.
Note:
Repeat test from the beginning as necessary
until the result has been accurately determined.
Isolate as per TOPs P4
and refit as necessary