16
Alternate Vent/Flue Location
The alternate vent/flue location is the large hole directly
in
line with the induced draft blower outlet. To use the al-
ternate vent/flue location refer to the following steps and
the “Alternate Vent/Flue Location” figure. This option is
not available with counterflow models.
NOTE: In the horizontal left installation position, a means
of condensate collection must be provided to keep vent
pipe condensate from entering the draft inducer housing.
If the vent drain elbow is eliminated from the installation,
an RF000142 kit must be used.
1. Remove the four screws from the vent pipe flange
on top the furnace.
2. Remove the internal elbow and vent pipe
3. Cut 2 1/2” from the flange .
4. Remove plastic plug in line with the inducer outlet
5. Install cut end of the flanged section and connect to
inducer with rubber coupling supplied with furnace.
6. Install screws removed in step 1 securing flange to
cabinet.
B
E
SURE
NOT
TO
DAMAGE
INTERNAL
WIRING
OR
OTHER
COMPONENTS
WHEN
REINSTALLING
COUPLING
AND
SCREWS
.
CAUTION
Figure 10
Alternate Combustion Air Provision
(Upflow / Horizontal models only)
When using the alternate venting location, either in a hor
-
izontal left side down installation or a vertical installation
using down – venting, an alternate combustion air opening
can be used. A locating dimple is located on the right side
of the furnace cabinet. The locating dimple is 1 7/8” mea-
sured from the front edge of the cabinet in line with the
knock out. To use the alternate combustion air location:
1. Remove screws and combustion air flange from
cabinet.
2. Insert cabinet plug in unused combustion air hole.
3. Drill a pilot hole at the cabinet dimple (size dictated
by knockout tool used).
4. Use a knockout tool to create a 3” diameter hole
5. Install combustion air flange and secure with screws
removed in step one.
MODEL
PIPE
SIZE
(4)
1
2
3
4
5
6
7
8
2
75
70
65
60
55
50
45
40
3
114
107
100
93
86
79
72
65
2
55
50
45
40
35
30
25
20
3
127
120
113
106
99
92
85
78
2
^
30
25
20
15
10
5
N/A
N/A
3
^
72
65
58
51
44
37
30
23
2
^
30
25
20
15
10
5
N/A
N/A
3
^
72
65
58
51
44
37
30
23
2
^
40
35
30
25
20
15
10
5
3
72
65
58
51
44
37
30
23
2
60
55
50
45
40
35
30
25
3
168
161
154
147
140
133
126
119
2
30
25
20
15
10
5
N/A
N/A
3
113
106
99
92
85
78
71
64
2
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
3
65
58
51
44
37
30
23
16
7,000 ft altitude or above use 3" pipe
^
*MES920402BN - add 20' of 2" pipe for upflow position
^
*MES920803BN - add 10' of 2" pipe for upflow position, add 66' of 3" pipe for upflow position
^
*MES920804CN - add 25' of 2" pipe for upflow position, add 58' of 3" pipe for upflow position
^ *MES920805CN - add 15' of 2" pipe for upflow position, add 58' of 3" pipe for upflow position
*MES921005CN
*MES921205DN
*MES92 Direct Vent
(2-Pipe)
and Non-Direct Vent
(1-Pipe) (6)
Maximum Allowable Length of Vent/Flue Pipe
(1) (2)
Number of Elbows
(3) (5)
*MES920603BN
*MES921004CN
*MES920403AN
*MES920803BN
*MES920804CN
*MES920805CN
1. Maximum allowable limits listed on individual lengths
for inlet and flue and NOT a combination.
2. Minimum requirement for each vent pipe if five (5)
feet in length and one elbow/tee.
3. Tee used in the vent/flue termination must be
included when determining the number of elbows
in the piping system.
4. 2 ½” or 3” diameter pipe can be used in place of 2”
diameter pipe.
5. Increased Clearance Configuration using (2) 45 deg.
elbow.
6. One 90° elbow should be secured to the combustion
air intake connection.
