Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect inline connector to return thermistor
Measurement:
Measure the resistance across the 2 pins for the return thermistor.
RESISTANCE RETURN THERMISTOR (S2)
Resistances vary with temperature and should conform approximately to the table below:
| Temperature Range (°C) | Resistance Range |
|---|---|
| 0°C to 10°C | 24.0kΩ - 39.0kΩ |
| 10°C to 20°C | 15.0kΩ - 24.0kΩ |
| 20°C to 30°C | 9.7kΩ - 15.0kΩ |
| 30°C to 40°C | 6.5kΩ - 9.7kΩ |
| 40°C to 50°C | 4.5kΩ - 6.5kΩ |
| 50°C to 60°C | 3.1kΩ - 4.5kΩ |
| 60°C to 70°C | 2.3kΩ - 3.1kΩ |
| 70°C to 80°C | 1.6kΩ - 2.3kΩ |
| 80°C to 90°C | 1.2kΩ - 1.6kΩ |
| 90°C to 100°C | 900Ω - 1.2kΩ |
Note: Clicking on the resistance table will switch between table and graph view.
Isolate as per TOPs P4
and refit as necessary