How can I test the original thermostat I removed from my TO 35? July 8, 2016.
You can test the old thermostat with buckets of hot and cold water, and a thermometer.
Drop the thermostat in a bucket of water heated to the opening temperature of the thermostat, it should be stamped on it. The thermostat should open. Next put the thermostat in the bucket of cold water, and it should close. If it opens and closes with the temperature changes, it is probably ok to use.