Immerse the thermostat in water, and then gradually heat the water.

Check the valve opening temperature of the thermostat.

• Standard valve opening temperature:
• 80 to 84°C (176 to 183°F)

If the valve opening temperature is not as specified, replace the thermostat.

Check the valve lift.

• Standard valve lift:
• 8.0 to 10 mm (0.315 to 0.394 in.) at 95°C (203°F)

If the valve lift is not as specified, replace the thermostat.

Check that the valve is fully closed when the thermostat temperature is below 77°C (171°F).

If the valve is not fully closed, replace the thermostat.