RESISTANCE DHW THERMISTOR AND HARNESS

Set Multimeter to Resistance

Isolate Mains Power to appliance as per TOPs P4
Gain access to PCB (use insulation mat as necessary)
Disconnect connector M5 from the PCB

Measure the resistance between the two red wires of connector M5.

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

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