Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Lower the Control panel and remove the PCB cover
Locate and Disconnect plug marked JP5
Locate and Disconnect plug marked JP5
Measurement:
Test 1:
With CH temperature selector set to maximum,
measure the resistance across the red wire (connection 1),
and the black wire (connection 2).
Resistance measured should be approximately 11 kOhms.
Turn CH temperature selector to minimum.
Resistance should reduce to less than 100 Ohms.
Test 2:
With CH temperature selector set at minimum, measure the resistance across the white wire (connection 3), and the black wire (connection 2).
Resistance measured should be approximately 11 kOhms.
Turn DHW temperature selector to maximum.
Resistance should reduce to less than 100 Ohms.
With CH temperature selector set to maximum,
measure the resistance across the red wire (connection 1),
and the black wire (connection 2).
Resistance measured should be approximately 11 kOhms.
Turn CH temperature selector to minimum.
Resistance should reduce to less than 100 Ohms.
Test 2:
With CH temperature selector set at minimum, measure the resistance across the white wire (connection 3), and the black wire (connection 2).
Resistance measured should be approximately 11 kOhms.
Turn DHW temperature selector to maximum.
Resistance should reduce to less than 100 Ohms.
Isolate as per TOPs P4
and refit as necessary