Display shows Sn2 or SN2, spa may shut down heating and display error continuously.

Safety: Disconnect power at the GFCI breaker before working in the equipment bay.

• Identify high-limit sensor: This sensor is typically clamped or threaded onto the heater tube separate from the main water sensor.
• Check mounting: Ensure the sensor is firmly attached to the heater surface or properly threaded into its port. A loose sensor can read incorrectly.
• Inspect wiring: Trace the sensor cable back to the control pack and verify the connector is fully seated and free of corrosion.
• Dry any moisture: If condensation or water is present around the control pack, dry the area thoroughly and correct any leaks.

If Sn2 remains after these checks, replace the high-limit sensor with an Evolution Spas-compatible part. If the error still does not clear, the control board may require professional diagnosis.