Harvia Heater Not Reaching Desired Temperature – How to Reset the Overheat Protector

Step 1 – Remove the heater cover to access the thermostat reset button. (Refer to the video we provided for guidance.)

Step 2 – Locate the small round reset button on the thermostat.

Step 3 – Before resetting, make sure the heater has been stored in a warm place (above 18°C) for some time. Then press the reset button firmly until you hear a click.

Step 4 – Check your sauna stones:

• Use the correct stones recommended for your heater.
• Rinse stones before placing to remove dust.
• Place larger stones at the bottom, loosely arranged for good airflow.
• Make sure the heating coils do not touch each other.
• Avoid covering heating elements or overloading stones.
• Replace or rearrange stones regularly, especially with frequent sauna use.

Step 5 – If the heater still doesn’t heat, please contact Nordhaus support directly for assistance.

Heater positioning

For proper performance and safety, our sauna heater must be installed 12 cm above the floor.

This clearance is essential to allow enough airflow around the heater, which helps with even heat circulation and efficient warming of the sauna.

If the heater is placed too low, airflow can be restricted. This may cause the heater to overheat or trigger the built-in overheat protection sensor.

Following the recommended height ensures your sauna heats effectively, protects the unit from damage, and improves the overall experience.