| 431 / | HD | COMBUSTION |
| 13 | DF | WITH INDICATOR OR INSPECTION MEANS {2} |
| 14 | DF | .~ Correlated with action of condition responsive burner control {1} |
| 15 | ![]() | .~.~ Shutdown or aborted start attempt indicated {1} |
| 16 | DF | .~.~.~> Responsive to gas leakage, overflow, abnormal pressure or electrical component malfunction |