Thermostat: Testing and Inspection

Replace thermostat if it is open at room temperature.
To test a closed thermostat:
1. Suspend the thermostat in a container of water as shown.
2. Heat the water, and check the temperature with a thermometer. Check the temperature at which the thermostat first opens and at full lift.

CAUTION: Do not let thermometer touch the bottom of the hot container.

Thermostat Testing:

3. Measure lift height of the thermostat when fully open.

STANDARD THERMOSTAT
Lift height: above 10 mm (0.39 inch)
Starts opening: 169 - 176°F (76 - 80°C)
Fully open: 194°F (90°C)