Set Appliance State:

Ensure appliance is cool
No demands for DHW or CH
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

If you are unsure which option to choose reset appliance and wait for appliance to complete self check otherwise select appropriate option below.
Note:
If appliance is igniting during your visit but you know it has ignition issues select intermittent fault, this will go through extra diagnostics to attempt to find fault.