Display shows Sn1 or SN1, spa may not heat or may shut down intermittently.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety: Turn off power at the GFCI breaker before accessing the control pack or heater.
- Locate temperature sensor: On most Evolution Spas, the main water temperature sensor is threaded into or inserted into a well on the heater tube.
- Check connection: Follow the sensor cable to the control pack and ensure the plug is fully seated and free of corrosion or moisture.
- Inspect cable: Look for cuts, abrasions, or rodent damage along the sensor wire.
- Reseat sensor: If the sensor is in a dry well, gently remove and reinsert it to ensure good contact. If threaded, verify it is snug but do not overtighten.
If Sn1 persists, the temperature sensor should be replaced with a compatible Evolution Spas thermistor. If replacing the sensor does not clear the error, the control board may be at fault and should be evaluated by a technician.
Repair Difficulty
Required Part
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