Set Appliance State:

CH Demand
Boiler CH thermostat set to MAX
Ensure CH system is cool
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance if required.
(press and hold the reset button for 4 seconds then release)
Does the boiler recognise the CH demand?
(CH demand is indicated by a radiator symbol
appearing in the display)
If the demand is recognised does the fan then run?
(There may be a delay of up to 60 seconds before
the fan runs after the boiler recognises demand)