Temperature readings of the sauna controller and the sauna thermometer differ

A slight difference between the measured temperatures is completely normal. It derives from the intrinsic error of measurement that applies to the devices. However, if the difference exceeds 10–15 °C (50-59 °F) degrees, you should check the temperature sensor and the sauna thermometer. Check the following:

• Are the temperature sensor and sauna thermometer placed in different locations in the steam room where the temperatures actually differ?
• Is the temperature sensor too close to the sauna heater? Is it too close to the door? The best location for the temperature sensor is the opposite wall of the sauna heater, approximately 15 cm (5,9 in) from the ceiling. It should not be placed close to vents or windows.
• Is the sauna thermometer functioning properly?

If none of the causes described above apply, and the following problems persist, the fault likely resides in the temperature sensor and it requires replacing:

• the temperature difference exceeds 20 ° (68 °F) degrees
• the temperature displayed on the screen of the sauna controller changes abruptly or fluctuates constantly
• The message “Temperature input error” is displayed on the screen of the sauna controller

The cable might also cause these problems. Take down the sensor and try connecting it to the main module with another suitable cable. If the sensor starts functioning properly, you’ll just need to replace the cable.