Sears 9MPD - Manual (Page 40)

10. Sequence of Operation & Diagnostics
The following is the normal operating sequence for the control system.
Cooling (Y) Request:
24 VAC signals applied to Y & G terminals of EFT (electronic fan timer) control.
• Cool motor speed energized after
6
second Cool Fan On Delay time.
Y & G signals removed from EFT.
• Cool motor speed de-energized after 60 second Cool Fan Off Delay time.
Circulating Fan (G) Request:
24 VAC signals applied to G terminals of EFT control.
• Heat motor speed energized without delay.
G signal removed from EFT.
• Fleat motor speed de-energized without delay.
Heating (W) Request:
24 VAC signals applied to W terminal of EFT control.
• Inducer motor turns on.
• The gas valve solenoid energizes.
• Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.
• After the pilot lights, the main burners energize and light.
• Timed from the opening of the main gas valve, the control will delay 30 seconds before switching the fan to Fleat speed.
W signal removed from EFT.
• The gas valve de-energizes and the main burners go out.
• The inducer runs at its present speed for a 30 second postpurge period.
• Timed from the gas valve de-energizing, the Fleat fan speed de-energizes after the selected Fleat Fan Delay time expires.
Heating Request with Gas Supply Line Shut Off:
24 VAC signals applied to W terminal of EFT control.
• Inducer motor turns on.
• The gas valve solenoid energizes.
• Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.
• The ignitor glows red-hot for 30 seconds, then turns off.
• The igniter stays off for 25 seconds, then begins to warm-up again.
• The igniter glows red-hot for 30 seconds, then turns off.
• The pilot valve closes 3 seconds after the igniter de-energizes.
• The inducer de-energizes 5 seconds after the pilot valve closes.
• The SmartValve proceeds to soft lockout and flashes error code
6
.
• The control exits soft lockout after 5 minutes and begins
another ignition sequence.
Gas Valve Diagnostic Codes (See Figure 43)
OFF
Fleartbeat
1 Flash
2 Flashes
3 Flashes
4 Flashes
5 Flashes
6 Flashes + 1
6 Flashes + 2
6 Flashes + 3
Control not powered
Normal Operation (Standby or call for heat)
Not used
Pressure switch closed when should be open
Pressure switch circuit was still sensed as open 30 seconds after the inducer was energized. System is
in 5 minute delay mode, with inducer off. After 5-minute delay, a new ignition sequence will be initiated.
(Note: SV9541M On/Off switch in off position during a call for heat will generate this diagnostic code)
Limit switch string open
Flame sensed out of sequence - Flame signal still present.
Note 1
Notes 1
Notes 1
6 Flashes + 4 Notes 1,2 =
7 Flashes =
Soft Lockout
Soft Lockout
Soft Lockout
During Run
Soft Lockout
Maximum retry count exceeded (failed to light within 4 trials for ignition)
Maximum recycle count exceeded - Last failure was Flame Sense Lost During Run
Maximum recycle count exceeded - Last failure was Airflow Proving Circuit Opened
Maximum recycle count exceeded - Last failure was Limit Circuit Opened During Run
Soft Lockout Due to Limit Trips Taking Longer than 2 minutes to Reset; Auto Reset After 1 Flour if
Call for Fleat Still Present. Reset by Cycling Call for Fleat at Any Time.
NOTE 1: The6 + X designation indicates a combination of flash codes: 6 flashes shows the control is in soft lockout, followed by X flashes
44001 1114 00