WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure
Mains Power On
Reset the service functions to factory settings by following the process below:

Measurement:

Step 1:
Press and hold the button marked with the picture
of a spanner for 10 seconds. The button will
illuminate orange and the display will show 1.A
Step 3:
Press the button marked ECO repeatedly until
8.E is present in the display.
Step 5:
Press and hold the chimney sweep button until
brackets appear in the display. The button can
then be released.
Step 7:
After air purge mode has completed the boiler will resume normal operation, display showing flow temperature.
Step 8:
Recheck pump overrun operation:
CH demand
Allow the boiler to run until the flow temp reaches 60°C.
Remove CH demand at clock or room stat.
With factory reset carried out does the pump now continue to overrun for approximately 3 minutes or less?
PUMP OVERRUN NOW AS ABOVE
PUMP OVERRUN STILL NOT AS ABOVE