27
O
O
O
O
O
P E R
P E R
P E R
P E R
P E RA
A
A
A
AT I O N A L
T I O N A L
T I O N A L
T I O N A L
T I O N A L
C
C
C
C
C
H E C K
H E C K
H E C K
H E C K
H E C KS
S
S
S
S
& S
& S
& S
& S
& S
A F E T
A F E T
A F E T
A F E T
A F E T Y
Y
Y
Y
Y
C
C
C
C
C
I R
I R
I R
I R
I RC U I T
C U I T
C U I T
C U I T
C U I T
D
D
D
D
D
E S
E S
E S
E S
E SC R I P
C R I P
C R I P
C R I P
C R I PT I O N
T I O N
T I O N
T I O N
T I O N
is shipped set on HIGH. High heat ships on MEDIUM and low heat is
shipped on MEDIUM-LO. These blower speeds should be adjusted
by the installer to match the installation requirements so as to pro-
vide the correct heating temperature rise and the correct cooling
CFM.
To adjust the circulator blower speed, proceed as follows:
1. Turn OFF power to the furnace.
2. Select the heating and cooling blower speeds that match
the installation requirements from the airflow table in the
Specification Sheet applicable to your model. (Please
contact
your distributor or our website for the applicable Specification
Sheet referred to in this manual.)
3. Relocate desired motor leads to the circulator blower heat
and cool speed terminals on the integrated control module.
(Terminals are identified as LO HEAT, HI HEAT and COOL (hot))
for *(M,D)H8 models and HEAT and COOL for *(M,H,D)S8
models). If a heating speed and the cooling speed are the
same, a jumper wire must be used between the heat and
cool terminals.
4. Connect all unused blower motor leads to the “PARK”
terminals on the integrated control module. Any leads not
connected to the “PARK” terminals must be taped.
5. Turn ON power to furnace.
6. Verify proper temperature rise as outlined in
Temperature
Rise section
.
C
C
C
C
C
IRCULATOR
IRCULATOR
IRCULATOR
IRCULATOR
IRCULATOR
B
B
B
B
B
LOWER
LOWER
LOWER
LOWER
LOWER
F
F
F
F
F
AN
AN
AN
AN
AN
T
T
T
T
T
IMING
IMING
IMING
IMING
IMING
A
A
A
A
A
DJUSTMENT
DJUSTMENT
DJUSTMENT
DJUSTMENT
DJUSTMENT
NOTE:
NOTE:
NOTE:
NOTE:
NOTE: Items in this section refer to the air circulator blower fan
air circulator blower fan
air circulator blower fan
air circulator blower fan
air circulator blower fan in
the *(M,D)H8 models, NOT to the induced draft blower. The induced
draft blower timing sequence is not adjustable. The circulator blower
fan timing is adjustable only on models with optional “heating fan
OFF delay” adjustment pins or switches. It is NOT adjustable in any
other circumstances.
As shipped, the circulator blower fan will remain on for 150 sec-
onds after the gas valve closes. When a call for cooling occurs, the
circulator fan comes on and remains on for 45 seconds after the call
for cooling ends. During normal heating operation, the circulator
fan will come on approximately 34 seconds after the gas valve
opens.
O
N
O
F
F
O
N
O
F
F
1
150
SECOND
DELAY
100
SECOND
DELAY
1
Switch viewed in an upflow installation.
Adjustment Switch
O
O
O
O
O
P E R
P E R
P E R
P E R
P E RA
A
A
A
ATIONAL
TIONAL
TIONAL
TIONAL
TIONAL
C
C
C
C
C
H E C K
H E C K
H E C K
H E C K
H E C KS
S
S
S
S
WARNING
T
O AVOID PERSONAL INJURY OR DEATH, DO NOT REMOVE ANY INTERNAL
COMPARTMENT COVERS OR ATTEMPT ANY ADJUSTMENT.
E
LECTRICAL
COMPONENTS ARE CONTAINED IN BOTH COMPARTMENTS.
C
ONTACT A
QUALIFIED SERVICE AGENT AT ONCE IF AN ABNORMAL FLAME APPEARANCE
SHOULD DEVELOP.
B
B
B
B
B
URNER
URNER
URNER
URNER
URNER
F
F
F
F
F
LAME
LAME
LAME
LAME
LAME
The burner flames should be inspected with the burner compart-
ment 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.
Check the burner flames for:
1. Good adjustment
2. Stable, soft and blue
3. Not curling, floating, or lifting off.
Burner Flame
A
A
A
A
A
UXILIARY
UXILIARY
UXILIARY
UXILIARY
UXILIARY
L
L
L
L
L
IMIT
IMIT
IMIT
IMIT
IMIT
C
C
C
C
C
ONTROL
ONTROL
ONTROL
ONTROL
ONTROL
Auto reset limits are located on or near the blower. To access this
auxiliary limit, disconnect the electrical power and remove the
blower door. The auxiliary limit control is designed to prevent fur-
nace operation in case of main blower failure on horizontal installa-
tions. It may also open if the power supply is interrupted while the
furnace is firing. The auxiliary limit control is suitable for both hori-
zontal right and horizontal left installations. Regardless of airflow
direction, it does not need to be relocated.
T
O
AVOID
PERSONAL
INJURY
OR
DEATH
,
DO
NOT
REMOVE
ANY
INTERNAL
COMPARTMENT
COVERS
OR
ATTEMPT
ANY
ADJUSTMENT
.
E
LECTRICAL
COMPONENTS
ARE
CONTAINED
IN
BOTH
COMPARTMENTS
.
C
ONTACT
A
QUALIFIED
SERVICE
AGENT
AT
ONCE
IF
AN
ABNORMAL
FLAME
APPEARANCE
SHOULD
DEVELOP
.
WARNING
S
SS
S
S
AFETY
AFETY
AFETY
AFETY
AFETY
C
C
C
C
C
IRCUIT
IRCUIT
IRCUIT
IRCUIT
IRCUIT
D
D
D
D
D
ESCRIPTION
ESCRIPTION
ESCRIPTION
ESCRIPTION
ESCRIPTION
G
G
G
G
G
ENERAL
ENERAL
ENERAL
ENERAL
ENERAL
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.
