Kentec Sigma XT 11030M2 and led S3?

What does the S3 led on this panel do? I’ts nothing to do with sounders. I’ve got S3 plus the Flooding zone leds alight. I’m trying to disable the extinguishant of the panel since its not needed in this situation and I have the required resistors and diode in place at the top of the panel. The manual says that these two indicators “indicate a common fault condition within the extinguishant section of the control panel” Anyone know what that fault could be?