Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Remove control box cover
Disconnect plug marked CH sensor
(6 way connector with 3 red leads, 1 white lead and 1 black lead)

Measurement:

Test 1:
With CH temperature selector set to MAX, measure the resistance across
the red wire (connection 1), and the black wire (connection 2).
Resistance measured should be approximately 9.5 kOhms.
Turn CH temperature selector to MIN.
Resistance should reduce to less than 100 Ohms.
Test 2:
With CH temperature selector set at MIN, measure the resistance across
the white wire (connection 3), and the black wire (connection 2).
Resistance measured should be approximately 9.5 kOhms.
Turn CH temperature selector to MAX.
Resistance should reduce to less than 100 Ohms.