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10. Sequence of Operation & Diagnostics
The following is the normal operating sequence for the control system.
Cooling (¥) Request:
24 VAC signals applied to Y & G terminals of EFT (electronic fan timer) control.
•Cool motor speed energized after 5 second Cool Fan On Delay time.
Y & G signals removed from EFT.
•Cool motor speed
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.
•Heat motor speed
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 Heat speed.
W signal removed from EFT.
•The gas valve
•The inducer runs at its present speed for a 30 second postpurge period.
•Timed from the gas valve
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
•The igniter stays off for 25 seconds, then begins to
•The igniter glows
•The pilot valve closes 3 seconds after the igniter
•The inducer
•The SmartValve proceeds to soft lockout and flashes error code 6.
•The control exits soft lockout after 5 minutes and begins another ignition sequence.
44001 102004 | [_ |