Error Code
Sn1 error code — Balboa spa
Always cut power at the breaker before opening the spa pack or touching wiring. Spa equipment runs at 120/240V and can be lethal. If you are unsure, hire a licensed spa technician.
Sn1 is a hard sensor failure, not an out-of-range reading — the board sees an open or short circuit. On Balboa systems Sn1 maps to the hi-limit sensor in the heater; the fix is nearly always the sensor or its harness.
What Sn1 means
Temperature sensor failed — open or shorted.
Diagnose in order
- Power-cycle at the breaker to rule out a transient fault
- Inspect the sensor harness and connector at the board for corrosion
- Replace the hi-limit sensor in the heater — Sn1 points there on Balboa systems
Likely failed parts
Frequently asked questions
Related codes & guides
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