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For Non-Direct Vent (1-Pipe) system, combustion-air must termi-
nate outside of furnace casing with 1 elbow. Orient elbow so that
its opening faces down for upflow or downflow applications.
Orient elbow so that its opening faces sideways (left or right) for
horizontal left or horizontal right applications (See Fig. 37.)
Maintain a 3-in minimum clearance between the opening of the
combustion-air inlet pipe and any object.
UNIT CORROSION HAZARD
Excessive exposure to contaminated combustion air may
result in safety and performance related problems.
Combustion air must not be taken from inside structure
because inside air is frequently contaminated by halogens,
which include fluorides, chlorides, bromides, and iodides.
These elements are found in aerosols, detergents, bleaches,
cleaning solvents, salts, air fresheners, adhesives, paint, and
other household products. Locate combustion-air inlet as far
as possible from swimming pool and swimming pool pump
house.
NOTE:
All pipe joints must have cemented attachment of
combustion-air inlet pipe to inlet housing connection, since it may
be necessary to remove pipe for servicing.
Assembly of Combustion Air Pipe (Non-Direct Vent/1-Pipe
System ONLY)
1. Permanently install perforated disk assembly (factory-
supplied in loose parts bag) in combustion-air elbow using
RTV or by cementing, as shown in Fig. 38. For 120,000 Btuh
size units only: separate the 2 halves of perforated disk
assembly and use only the shouldered disk half.
2. Determine the length of straight portion of combustion-air
inlet pipe from Fig. 38.
3. Cut field-supplied 2-in. diameter PVC pipe to length as
determined per Fig. 38.
4. Permanently attach elbow/perforated disk assembly to straight
portion of pipe using RTV or by cementing as shown in Fig.
38.
Assembly of Combustion Air Pipe (Direct Vent-2-Pipe
System ONLY)
1. Using Table 11, determine the smallest combustion air diam-
eter permitted. Pick the larger diameter and use it for both
combustion and vent pipe.
NOTE:
Do not count elbows or pipe sections in terminations or
within furnace (All elbows shown in Fig. 42 and Fig. 43 are not to
be counted).
UNIT MAY NOT OPERATE
Failure to follow this caution may result in incomplete
combusiton, flame disturbance, or flame sense lockout.
When installing combusiton air and vent system of short pipe
length, the smallest allowable pipe diameter must be used.
NOTE:
A 2-in. diameter pipe must be used within furnace casing.
Make all pipe diameter transitions outside furnacec casing per Fig.
39.
Fig. 36—Furnace Control
A02142
BL
W
NUETRAL
ST
A
TUS CODE LED
SEC-2 SEC-1
EAC-2 L2
FUSE 3-AMP
0.5 AMP@24VAC
HUM
TEST/TWIN
Y1 DHUM G COM
W/W1
Y/Y2 R
24V
PL
T
120 180
90 150
BLOWER OFF-DELAY
PL
T 1
COOL HEA
T
SPARE-1 SPARE-2
FAN
EAC-1
1-AMP@
115VAC
PR-1
L1
PL2 1
24-V THERMOSTAT
TERMINALS
3-AMP FUSE
LED OPERATION &
DIAGNOSTIC LIGHT
115-VAC(L2)NEUTRAL
CONNECTIONS
COOL
HEAT
SPARE-1
SPARE-2
FAN
BLOWER SPEED
SELECTION TERMINALS
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
115 VAC (L1) LINE
VOLTAGE CONNECTION
PL2-HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
PL1-LOW VOLTAGE MAIN
HARNESS CONNECTOR
TRANSFORMER 24-VAC
CONNECTIONS
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX.)
TWINNING AND/OR
COMPONENT TEST
TERMINAL
BLOWER OFF-DELAY
30