Set Appliance State:

Mains Power Off
Ensure NO Demands
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Reset the appliance as necessary (hold down both arrow buttons until display changes).
Ensure boiler is in ECO mode (press eco button to toggle on / off).
The appliance should now complete a self-check of approx.10 seconds where the pump runs then enters standby, the pump should stop running and boiler should not attempt to fire.
If the system pressure is low boiler should display a warning.
Enter the installer mode and access level 1 - A2.
(click here for information on how to do this)
If the boiler has a minor fault code it will then be displayed.
If no fault is displayed (0 shown) you can use the back button to return to the main menu.