American Dryer Corp. ML-175DR - Manual (Page 46)

42 American Dryer Corp. 113406-1
2. For Models with Direct Spark Ignition (DSI) Module (Type I)
Theory of Operation:
Start the drying cycle. When the gas burner ignites within the
chosen trial for ignition time (6-seconds), the flame sensor detects
gas burner flame and signals the DSI module to keep the gas
valve open as long as there is a call for heat. The DSI module
will “LOCKOUT” if the gas burner flame is not sensed at the
end of the trial for ignition period. The trial for ignition period will
be repeated for a total of three (3) retries/trials (the initial try and
two [2] more retries/trials). If the flame is not sensed at the end
of the third retry/trial (inter-purge period of 30-seconds) the DSI
module will “LOCKOUT” (light emitting diode [L.E.D.] diagnostic
indicator flashes).
A steady L.E.D. indicator indicates normal operation.
No L.E.D. indicator indicates a power or an internal failure has occurred.