Set Appliance State:
Mains Reset Switch OFF
Set Multimeter to AC Volts 
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Release the front facia by gently prising up the retaining
latches at the top of the facia
Set DHW temperature selector to Off
Release the front facia by gently prising up the retaining
latches at the top of the facia
Set DHW temperature selector to Off
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Mains reset switch On.
Measure voltage at terminal 2 (centre connection) on the green terminal block situated on the controls interface PCB and a suitable neutral.
Mains voltage expected.
Mains power Off.
Measure voltage at terminal 2 (centre connection) on the green terminal block situated on the controls interface PCB and a suitable neutral.
Mains voltage expected.
Mains power Off.
Isolate as per TOPs P4
and refit as necessary