Sn2
Saratoga Spas High-Limit Sensor Fault

Display shows Sn2, SN2, or SENSOR 2, spa may shut down heater or display incorrect temperature.

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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.

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Possible Causes

Failed high-limit sensor, Loose sensor connection at control board, Sensor not fully inserted into heater tube, Damaged sensor cable

How to Fix / Troubleshooting

Safety: Disconnect power before working in the equipment bay.

  • Locate high-limit sensor: Identify the second sensor on the heater tube (often labeled HI-LIMIT or SENSOR 2 on the board).
  • Verify insertion: Make sure the sensor is fully seated in its dry well and secured. A partially inserted sensor can misread temperature.
  • Inspect and reseat connector: Trace the cable to the control board and unplug/replug the connector to clean the contacts.
  • Check for cable damage: Look for signs of rodent damage or abrasion where the cable passes through bulkheads.

If Sn2 remains after these checks, replace the high-limit sensor. Continued Sn2 with a new sensor suggests a control board fault that should be diagnosed by a technician.

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Repair Difficulty

Medium 3/5

Required Part

High-Limit Sensor
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