Yes, this is completely normal.
Our temperature controllers are mechanical and have a certain tolerance range. Typically, they are designed to turn on around 3°C (about 37°F) and turn off around 10°C (about 50°F). However, there is typically a tolerance of about ±3°C. That means some units may activate slightly earlier or later than others.
If you want to test whether the controller is working correctly, you can place the thermostat portion in an ice water mixture (about 0°C or 32°F). As long as it turns on at that freezing point, it’s functioning as intended. The purpose is to prevent freezing, so as long as it activates before freezing conditions, there’s no need to worry about minor differences between units.




