7
Figure 9 - Locations of Screws in Back
of Furnace Cabinet (25,000 BTU/Hr
Model)
Figure 10 - Locations of Screws in
Back of Furnace Cabinet (40,000
BTU/Hr Model)
Figure 11 - Removing Screws on Lower
Flange (40,000 BTU/Hr Model Shown)
Figure 13 - Location of Knockout Plug
Figure 14 - Inserting Pipe through
Knockout Hole
Figure 12 - Disconnecting Gas Inlet Pipe
(40,000 BTU/Hr Model Shown)
Figure 8 - Connecting Gas from Inside of
Room
INSTALLATION
(Continued)
Connecting Furnace to Gas
Supply at Front of Furnace
1. Locate gas inlet pipe on lower, right
front of furnace (see Figure 8).
2. Connect 3/8" NPT pipe or nipple to
gas inlet pipe (see Figure 8). See
Providing Gas Piping to Furnace
for
correct gas pipe installation.
Connecting Furnace to Gas
Supply at Rear of Furnace
1. Remove the two screws in back of fur-
nace cabinet located by the exhaust
vent(s) (see Figures 9 and 10).
2. Remove two screws on front lower
flange that attach furnace flange to
furnace cabinet flange (see Figure
11).
Note:
40,000 BTU/Hr model has
a bottom shield (see parts list, page
19, for location). Removing two
screws will detach bottom shield.
3. Slide furnace out of furnace cabinet.
4. Locate gas inlet pipe on lower, right
front of furnace.
5.
40,000 BTU/Hr Model Only:
Remove
screw holding gas inlet pipe clamp to
furnace. (See Figure 12).
6. Disconnect gas inlet pipe from 3/8"
manifold elbow. Turn gas inlet pipe
counterclockwise to disconnect (see
Figure 12).
7. Rotate the 3/8" manifold elbow 90
/
so
the opening is pointing downward
(see Figure 12).
8. Locate knockout plug in furnace cabi-
net. Knockout plug is in lower left rear
of furnace cabinet (as viewed from
rear, see Figure 13). Remove
knockout plug.
9. Slide furnace back into furnace cabi-
net. Make sure exhaust tube gaskets
are in place. Make sure exhaust and
intake vent tubes extend into vent
caps on back of cabinet. Replace two
screws by exhaust vent(s) removed in
step 1.
10.
25,000 BTU/Hr Model:
Replace two
screws removed in step 2. Attach fur-
nace flange and furnace cabinet
lower flange together.
40,000 BTU/Hr Model:
Place bottom
shield back in place. Replace two
screws removed in step 2. Attach bot-
tom shield, furnace flange, and
furnace cabinet lower flange together.
11. Run 3/8" pipe or nipple through
knockout hole. Connect 3/8" pipe or
nipple to manifold elbow (see Figure
14). See
Providing Gas Piping to
Furnace
for correct gas pipe instal-
lation.
CAUTION: Lightly apply pipe joint
sealant to male threads before
connecting. Use pipe joint sealant
that is resistant to liquid petroleum
(LP) gas.
12. Check connections for gas leak.
WARNING: Never use an open
flame to check for a leak. Apply a
mixture of liquid soap and water to
all joints. Bubbles forming show a
leak. Correct all leaks at once.
13. Caulk around pipe or nipple. This pre-
vents cold air entering knockout hole.
8
INSTALLATION
(Continued)
Providing Gas Piping to Furnace - Propane (LP) Gas Only
See Next Page for Natural Gas Piping
You must provide gas piping from gas source to furnace. The gas piping must be in a vertical position where it connects to the furnace.
This prevents interference with front cover installation.
Consult your local gas company for proper routing of the gas lines.
Pipe size is determined by the length of pipe from the gas source to the furnace and the total BTU load on the gas source.
Add the total BTUs required for all appliances connected to the gas source including this furnace. Divide this number by 2500. This
will give you the approximate cubic feet per hour needed.
Example:
40,000
BTU/Hr
+ 15,000
BTU/Hr for other gas appliances
55,000
BTU/Hr total
55,000 ÷ 2500 = 22
Locate 22 or higher on chart below.
According to the chart below, you should use 40 feet or less of 3/8" pipe, 125 feet
or less of 1/2" pipe, etc....
MINIMUM
RON PIPE
SIZE
LENGTH OF PIPE (FEET)
10
20
30
40
50
60
70
80
90
100
125
150
175
200
3/8"
47
32
26
22
19
18
16
15
14
13
12
11
10
—
1/2"
87
61
48
42
37
33
30
28
26
25
22
20
18
17
3/4"
184
126
100
86
76
69
63
59
55
52
48
42
39
36
1"
344
232
189
162
142
129
119
112
106
99
86
79
73
66
1¼"
696
484
391
331
291
265
245
232
212
202
182
166
149
139
1½"
1060
729
590
504
444
404
371
351
324
305
272
252
232
212
2"
2022
1392
1094
961
842
762
696
656
616
576
517
470
430
404
2½"
3182
2188
1790
1524
1326
1226
1127
1060
994
928
829
749
969
649
3"
5635
3911
3116
2718
2387
2154
1989
1856
1724
1657
1458
1326
1226
1127
4"
11602
7956
6431
5503
4906
4508
4110
3845
3580
3381
2983
2718
2519
2320
IMPORTANT:
Check gas line pressure at gas meter before connecting furnace to gas line. Gas line pressure must be no less than
11 inches of water and no greater than 13 inches of water. Gas pressures and input to the burners must not exceed the rated input
and pressure shown on the rating plate. For propane/LP gas, manifold pressure should be 10 inches of water. For elevations above
2000 feet, reduce rating 4% for each 1000 feet above sea level (U.S.A. only).
CAUTION: Never connect heater directly to the propane/LP supply. This heater requires an external regulator (not
supplied). Install the external regulator between the heater and propane/LP supply.
The installer must supply an external regulator. The external regulator will reduce incoming gas pressure. You must reduce incoming
gas pressure to between 11 and 14 inches of water. If you do not reduce incoming gas pressure, heater regulator damage could
occur. Install external regulator with the vent pointing down. Pointing the vent down protects it from freezing rain or sleet.