Thermostat: Testing and Inspection

1. Visually check that the thermostat valve is airtight.
2. Place the thermostat and a thermometer in water.





3. Heat the water and check the following:

Initial-opening temperature
Main: 86.5 - 89.5°C (188 - 193°F)
Sub : 83.5 - 86.5°C (183 - 187°F)
Full-open temperature
100°C (212°F)
Full-open lift
Main: 8.0mm (0.31 in) min.
Sub: 1.5mm (0.O6 in) min.

4. Replace the thermostat if it fails any of the above tests.