Table of Contents
Advertisement
•
Igniter warm up begins upon presence of closed pressure switch contacts.
•
Gas valve opens at end of igniter warm up period, delivering gas to burners and establishing flame.
•
Integrated control module monitors flame presence. Gas valve will remain open only if flame is detected.
•
Circulator blower is energized on heat speed following a thirty (30) second blower on delay.
•
Furnace runs, integrated control module monitors safety circuits continuously.
•
R and W thermostat contacts open, completing the call for heat.
•
Gas valve closes, extinguishing flame.
•
Induced draft blower is de-energized following a fifteen second post purge.
•
For 96% Models: Circulator blower continues running for the selected heat off delay period Factory set at 150
seconds.
For 92% Models: The blower off delay is 150 seconds (non-adjustable).
•
Furnace awaits next call from thermostat.
C
M
OOLING
ODE
The normal operational sequence in cooling mode is as follows:
•
R,Y, G thermostat thermostat contacts close, initiating a call for cool.
•
Integrated control module performs safety circuit checks.
•
Outdoor fan and compressor are energized.
•
Circulator blower is energized on the cool speed.
•
Furnace circulator blower and outdoor cooling unit run their appropriate speeds, integrated control module monitors
safety circuits continuously.
•
R,Y, G thermostat contacts open, completing the call for cool.
•
Outdoor fan and compressor are de-energized.
•
Circulator blower continues running during a cool off delay period of 45 seconds.
•
Furnace awaits next call from thermostat.
F
O
M
AN
NLY
ODE
The normal operational sequence in fan only mode is as follows:
•
R and G thermostat contacts close, initiating a call for fan.
•
Integrated control module performs safety circuit checks.
•
Circulator blower is energized on heat speed.
•
Circulator blower runs, integrated control module monitors safety circuits continuously.
•
R and G thermostat contacts open, completing the call for fan.
•
Circulator blower is de-energized.
•
Furnace awaits next call from thermostat.
O
C
PERATIONAL
HECKS
The burner flames should be inspected with the burner compartment door installed. Flames should be stable, quiet, soft, and blue
(dust may cause orange tips but they must not be yellow). Flames should extend directly outward from the burners without curling,
floating, or lifting off. Flames must not impinge on the sides of the heat exchanger firing tubes.
S
C
D
AFETY
IRCUIT
ESCRIPTION
A number of safety circuits are employed to ensure safe and proper furnace operation. These circuits serve to control any potential
safety hazards and serve as inputs in the monitoring and diagnosis of abnormal function. These circuits are continuously monitored
during furnace operation by the integrated control module.
I
C
M
NTEGRATED
ONTROL
ODULE
The integrated control module is an electronic device which, if a potential safety concern is detected, will take the necessary
precautions and provide diagnostic information through an LED.
36
Hide quick links:
Advertisement
Table of Contents
Troubleshooting
