If your sauna is running but struggling to hit its maximum temperature, there are several things worth checking before reaching out to support. Work through each one below and it will likely point you to the cause.

Please take photos or videos at each step of the troubleshooting process. If we need to order replacement parts, our Support team will use these to process your warranty claim.

Note: Maximum temperatures by model: 175°F for the 3-Person and 2-Person 240V | 160°F for the 2-Person 120V.

1. Check the Vents

This is the most common culprit. If all three vents are open during heat-up, a significant amount of heat is escaping the cabin before it can build up.

• Close all three vents during heat-up for best performance.
• Once you’re inside and using the sauna, you can open the vents to improve airflow and keep CO₂ levels comfortable.

2. Check the Tower Heater Bulbs

Each tower heater contains two bulbs. With the sauna powered on, confirm that all four bulbs across both tower heaters are lit. A burnt-out bulb reduces the total heat output of that heater. If any are out, refer to the How to Replace a Tower Heater Bulb guide.

3. Do a Touch Test on the FIR Panels

After the sauna has been running for at least 5 minutes, press the back of your hand against the black fabric covering each FIR panel zone:

• Left and right side walls
• Left, center, and right sections of the back wall
• Calf panel

Every zone should feel noticeably warm. A cool section indicates a panel that isn’t heating. If you find one, refer to the relevant How to Replace an Infrared Heater Panel guide for that panel’s location.

4. Check the Door Seal

• Magnet contact: Close the door and confirm all door magnets are making full contact with their mating strips on the front glass panels. A door that isn’t sealing properly lets heat escape continuously.
• Door seals: Check that a clear rubber seal is present and intact along both the top and bottom edges of the glass door.

5. Check the Incoming Voltage

Lower-than-expected incoming voltage from your electrical circuit can directly impact heating performance. If all of the above check out and your sauna is still underperforming, voltage may be a factor. Contact Plunge Support for more details on how to assess this.

Still Not There? Contact Support

If you’ve worked through everything above without finding the cause, reach out to Plunge Support. To help us diagnose the issue quickly, please have the following ready:

• The temperature your sauna reached after 1 hour of runtime
• The average ambient temperature of the room the sauna is installed in