Set Appliance State:

Mains Power Off
Set Multimeter to AC Volts Set meter to measure AC Volts
CH Demand
Selector switch in winter position
Timer switched to FIX ON
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure mains voltage on J2 connection 3 (brown L)
and J5 terminal 2 (blue N).