Page 36 Part # MCOSM06 Rev 1 (11/03/08)

Fig 3 Sequence of Operation
Start
Thermostat
call for heat
Prepurge
Trial for
ignition
Main valve
ame sensed?
Yes
No
Interpurge
Maximum
number of trials
attempted?
No Yes
Ignition lookout
(optinal LED
ashes)
No Control
with ignition
recycle?
Yes
Yes
Recycle delay
period
Flame present when
not expected
No Yes
Flame
present for
30 seconds?
Detected fault
Hard Lockout
(optional LED
turns o)
Run
Flameout?
Yes
Sixteenth
ameout?
No
No
Yes
Thermostat
callin for heat?
No
De-energize
control and valves
End