9. Furnace Maintenance
CAUTION
It is recommended that the furnace be inspected and
serviced on an annual basis (before the heating
season) by a qualified service technician.
See "User's Information Manual" and the "Service
Manual".
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 Coo! Fan On Delay time.
Y & G signals removed from EFT.
• Cool motor speed de-energized after 60 second Coo! Fan Oft 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.
• Heat 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 wil! delay 30 seconds before switching the fan to Heat 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 Heat fan speed de-energizes after the selected Heat Fan Delay time expires.
Heating Requestwith Gas Supply LineShut 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 oft 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.
440 01 101004 [_
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