Set Appliance State:

Mains Power Off
CH Demand
On/Off Switch in ON position
Mode Selector Switch to Constant
Heating Thermostat to MAX
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Run boiler for approximately one minute. Ensure there is no rapid increase in system pressure. Pressure should remain in the 'blue' area of the pressure gauge.
NOTE:
Remember the C/H delay timer - the boiler will not fire immediately. There will be approximately a two minute wait.