Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove connector from DHW flow sensor
Measurement:
Measure the resistance (continuity) across the DHW flow sensor harness leads.
Connections are;
X10 connector pins 1,2 & 3 to corresponding connection on flow sensor connector.
Expected resistance is continuity (zero resistance).
Note.
Ensure a good connection is made or misdiagnosis will occur.
Connections are;
X10 connector pins 1,2 & 3 to corresponding connection on flow sensor connector.
Expected resistance is continuity (zero resistance).
Note.
Ensure a good connection is made or misdiagnosis will occur.
Isolate as per TOPs P4
and refit as necessary