Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
On/Off Switch ON
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary (hold reset button for 5 seconds then release).
Monitor the operation of the fan.
How does the fan behave?
Note:
If necessary repeat test as required to observe fan operation.