12 18-CD35D1-1
INSTALLER’S GUIDE
TABLE 8
CABINET
WIDTH
FILTER
SIZE
FILTER BRACKET
LOCATION *
14-1/2"
2 - 14X20X1
12-7/8"
17-1/2"
2 - 16X20X1
14-3/8"
21"
2 - 16X20X1
13-1/8"
24-1/2"
2 - 16X20X1
11-5/8"
* Location dimension is from end of duct to the screw holes for the
bracket.
TABLE 9
CABINET
WIDTH
RETURN
DUCT
WIDTH
FILTER ACCESS
OPENING -
DIMENSION "A"
FILTER ACCESS
OPENING -
DIMENSION "B"
14-1/2"
13-1/4"
12"
14"
17-1/2"
16-1/4"
15"
14"
21"
19-3/4"
19-1/2"
14"
24-1/2"
23-1/4"
22"
14"
GENERAL VENTING
IMPORTANT:
These furnaces may be installed as Direct Vent
(sealed combustion) or as Non-direct vent
(single pipe). The furnaces are shipped DIRECT
VENT with sealed combustion. Please refer to
Table 11 and 12 for maximum vent length.
For DIRECT VENT APPLICATION: The furnaces
must be vented to the exterior of the house and
combustion air MUST come through the inlet air
pipe FROM OUTSIDE AIR.
For NON-DIRECT VENT APPLICATION: The
furnace shall be vented to the exterior of the
house, but combustion air may enter from
the surrounding area as long as combustion
air requirements are met. (See AIR FOR
COMBUSTION AND VENTILATION)
THIS FURNACE MUST BE VENTED TO THE OUTDOORS.
THESE FURNACES ARE INDUCED DRAFT VENTED AND
MUST
NOT
BE CONNECTED TO ANY VENT SERVING
ANOTHER APPLIANCE. PLEASE NOTE THAT THESE
FURNACES USE
POSITIVE-PRESSURE
VENT SYSTEMS.
Proper venting is essential to obtain maximum efficiency from
a condensing furnace. Proper installation of the vent system
is necessary to assure drainage of the condensate and prevent
deterioration of the vent system.
American Gas Association has certified the design of condensing
furnaces for a minimum of 0" clearance from combustible
materials with a single wall plastic vent pipe.
The recommended system is assembled from 2", 2-1/2", or
3" plastic pipe and fittings (See Table 10). Where the system
is routed to the outdoors through an existing masonry chimney
containing flue products from another gas appliance, or where
required by local codes, then 3" venting of Type 29-4C stainless
steel must be used in place of PVC material.
These furnaces have been classified as CATEGORY IV furnaces
in accordance with the latest edition of ANSI Z21.47 • CAN/
CGA-2.3 Standards. Category IV furnaces operate with positive
vent pressure and with a vent gas temperature less than 140°F
above the dew point. These conditions require special venting
systems, which must be gas tight and water tight.
NOTE:
When an existing furnace is removed from a
venting system serving other gas appliances,
the venting system is likely to be too large to
properly vent the remaining attached appliances.
The following steps shall be followed with each appliance
remaining connected to the common venting system placed in
operation, while the other appliances remaining connected to the
common venting system are not in operation.
1. Seal any unused openings in the common venting system.
2. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion or other deficiencies which
could cause an unsafe condition.
3. Insofar as is practical, close all building doors and
windows and all doors between the space in which the
appliances remaining connected to the common venting
system are located and other spaces of the building. Turn
on clothes dryers and any appliances not connected to
the common venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they will
operate at maximum speed. Do not operate a summer
exhaust fan, close fireplace dampers.
4. Follow the lighting instructions. Place the appliance
being inspected in operation. Adjust thermostat so
appliance will operate continuously.
5. Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame of a
match or candle.
6. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
door, windows, exhaust fans, fireplace dampers and any
other gas-burning appliance to their previous conditions
of use.
If improper venting is observed during any of the above tests,
the remaining common venting system must be corrected.
Correction of the remaining common vent system should be
done by referring to the latest edition of the National Fuel Gas
Code (ANSI Z223.1) • CAN/CGA B149.1 Installation Codes
