Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove electrical connector from DHW flow sensor
Measurement:
Measure the resistance (continuity) across the flow sensor harness leads.
Connections are:
CN2 connector pins 42,43 & 45 to corresponding connection on flow sensor connector.
Expected resistance is continuity (zero resistance).
Also visually inspect the harness throughout its entire length and its connectors for any shorts / water ingress.
Connections are:
CN2 connector pins 42,43 & 45 to corresponding connection on flow sensor connector.
Expected resistance is continuity (zero resistance).
Also visually inspect the harness throughout its entire length and its connectors for any shorts / water ingress.
Isolate as per TOPs P4
and refit as necessary