Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap ON
DHW Temperature Control to MAX
Unclip Diverter Valve head from the body and leave in a safe position
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Place boiler in service mode. CLICK HERE FOR INSTRUCTIONS
Test 1. Turn the CH control knob to MAXIMUM and measure the CO2 with the appliance operating at MAXIMUM output.
Readings should be within the parameters outlined in the manufacturer’s instructions.
Test 2. Turn the CH control knob to MINIMUM and measure the CO2 with the appliance operating at MINIMUM output.
Readings should be within the parameters outlined in the manufacturer’s instructions.
Note:
Refit diverter valve head to body after test.