Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Turn Hot Water Tap On
Gain access to PCB (use Insulation Mat as required)
Selector switch to DHW position
CH temperature selector to minimum
DHW temperature selector to maximum
Selector switch to DHW position
CH temperature selector to minimum
DHW temperature selector to maximum
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow the fan to run.
While the fan is running monitor the voltage between connections 28 (Brown) and 29 (Blue) of the M5 connector on the PCB.
Does the mains voltage remain constant while the fan is running or does it reduce and fluctuate?
While the fan is running monitor the voltage between connections 28 (Brown) and 29 (Blue) of the M5 connector on the PCB.
Does the mains voltage remain constant while the fan is running or does it reduce and fluctuate?
Isolate as per TOPs P4
and refit as necessary