RESISTANCE DHW SENSOR AND HARNESS

Isolate Mains Power to appliance as per TOPs P4

Set Multimeter to Resistance

Remove ST9 connector from the PCB
If available use the Worcester test PCB to assist resistance test

Measure for resistance across the orange wires, terminals
17 & 18 of connector ST9.

Note: Clicking on the resistance table will switch between table and graph view.

The colours of the wires may vary but the terminal positions will remain the same.

Resistances vary with temperature and should conform approximately to the table below: