Goodman Amana AMH8 Service Instructions Manual page 38

PRODUCT DESIGN
(M DIP S
ODE WITCH IS SET TO
The normal operational sequence in sequence is as fol-
lows:
• R and W thermostat contacts close, initiating a
call for heat.
• Integrated control module performs safety circuit
checks.
• Induced draft blower is energized for 15 second
prepurge period causing pressure switch contacts
to close.
• Igniter warm up begins after 15 second prepurge
expires.
• Low and high-stage gas valves open at end of ig-
niter warm up period, delivering gas to burners
and establishing flame.
• High-stage gas valve closes after five seconds;
low-stage gas valve remains open.
• Integrated control module monitors flame pres-
ence. Gas valve will remain open only if flame is
detected.
• Circulator blower is energized on low heat speed
following a fixed thirty second blower on delay.
Electronic air cleaner terminals are energized with
circulator blower.
• Furnace is now operating in low-stage heating
mode.
• Furnace operates; integrated control module moni-
tors safety circuits continuously.
• If low-stage delay period expires, control will shift
operation from low-stage heating mode operation
to high-stage heating mode operation. Control will
energize circulator blower high heat speed and high
stage gas valve.
• Furnace is now operating in high-stage heating
mode.
• R and W thermostat contacts open, completing
the call for heat.
• Induced draft blower is de-energized following a
fifteen second post purge.
• Circulator blower is de-energized following a heat
off delay period (selectable 100 or 150 seconds;
factory set at 150 seconds).
The circulator blower will continue to run at cur-
rent heat speed for the duration of the cool down
period.
• Furnace awaits the next call from thermostat.
38
"2 STG" )
POSITION
C M
OOLING ODE
The normal operational sequence in cooling mode is as
follows:
• R and Y 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 cool speed fol-
lowing a fixed five second on delay. Electronic air
cleaner terminals are energized with circulator
blower.
• Furnace circulator blower and outdoor cooling unit
run, integrated control module monitors safety cir-
cuits continuously.
• R and Y thermostat contact open, completing the
call for cool.
• Outdoor fan and compressor are de-energized.
• Circulator blower is de-energized following a fixed
forty five second cool off delay period. Electronic
air cleaner terminals are de-energized.
• Furnace awaits the 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 low heat speed.
Electronic air cleaner terminals are energized.
• 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. Electronic air
cleaner terminals are de-energized.
• Furnace awaits the next call from thermostat.