Snb,  Sb,  or  SENSOR B SERVICE REQD  Message

"Sensor B" (Snb or Sb) is Not Operating Correctly.

The Sensor Connected to the "Sens.B" Connector on the System Board may have failed and Spa Functions are Disabled.  Check and Test Sensor B, Cable, and Connector for Damage, Connection, and Operation, or Continue for a Detailed Test Procedure.