Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
For access behind the control panel.
Release the fixing screw located at the top of the case front panel and lift the panel upwards from its locating pins and then forwards from the boiler. Remove the two fixing screws that secure the control panel and lower the panel.
For access to the control panel components.
Remove the five screws securing the rear cover and careful raise the cover from the control panel. When replacing the cover ensure no wires are trapped and all the wiring is secured secure with screws previously removed do not over tighten.
Release the fixing screw located at the top of the case front panel and lift the panel upwards from its locating pins and then forwards from the boiler. Remove the two fixing screws that secure the control panel and lower the panel.
For access to the control panel components.
Remove the five screws securing the rear cover and careful raise the cover from the control panel. When replacing the cover ensure no wires are trapped and all the wiring is secured secure with screws previously removed do not over tighten.
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
With all controls Off and thermostats satisfied NOT calling for heat.
Check for voltage across the terminals marked SL LIVE (red wire ) and the terminal marked N (blue wire) .
Expected voltage mains voltage (230AC).
Check for voltage across the terminals marked SL LIVE (red wire ) and the terminal marked N (blue wire) .
Expected voltage mains voltage (230AC).
Isolate as per TOPs P4
and refit as necessary