!!
critical Silvercrest

Error Code S A

Spa is shut down because the sensor plugged into the 'A' jack has failed or malfunctioned.

? What Causes This

Faulty sensor in plug socket ‘A’

How to Fix It

Verify the correct operation of the sensor and contact service if not.

Source: page 8 of the official manual

From the manual

Manual page 8 — Silvercrest error S A

This error code appears in:

Silvercrest Sfb 80 A1 Foot Spa