![background image](http://html.mh-extra.com/html/carrier/986tc/986tc_installation-start-up-operating-and-service-and-maintenance-instructions_2562914004.webp)
4
duct(s) sealed to the furnace casing and terminating outside
the space containing the furnace. See “Air Ducts” section.
8. A gas--fired furnace for installation in a residential garage
must be installed as specified in the warning box in the
“Location” section.
9. The furnace may be used for construction heat provided that
the furnace installation and operation complies with the first
CAUTION
in the
LOCATION
section of these instruc-
tions.
10. These Multipoise Gas--Fired Furnaces are CSA design--cer-
tified for use with natural and propane gases (see furnace
rating plate) and for installation in alcoves, attics, base-
ments, closets, utility rooms, crawlspaces, and garages. The
furnace is factory--shipped for use with natural gas. A CSA
(A.G.A. and C.G.A.) listed accessory gas conversion kit is
required to convert furnace for use with propane gas.
11. See Table 1 for required clearances to combustible con-
struction.
12. Maintain a 1--in. (25 mm) clearance from combustible ma-
terials to supply air ductwork for a distance of 36 in. (914
mm) horizontally from the furnace. See NFPA 90B or local
code for further requirements.
Table 1 – Minimum Clearances to Combustible Materials for
All Units
POSITION
CLEARANCE
Rear
0 (0 mm)
Front (Combustion air
openings in furnace and in
structure)
1 in. (25 mm)
Required for service
*24 in. (610 mm)
All Sides of Supply Plenum
*1 in. (25 mm)
Sides
0 (0 mm)
Vent
0 (0 mm)
Top of Furnace
1 in. (25 mm)
* Consult local building codes.
13. These furnaces SHALL NOT be installed directly on carpet-
ing, combustible tile, or any other combustible material oth-
er than wood flooring. In downflow installations, factory
accessory floor base MUST be used when installed on com-
bustible materials and wood flooring. Special base is not re-
quired when this furnace is installed on a manufacturer’s
specified coil assembly or coil box (see furnace clearance
label).
Important Installation and Start--up Procedures
Failure to follow this procedure may result in a nuisance
smoke or odor complaint.
The manifold pressure, gas rate by meter clocking,
temperature rise and operation must be checked after
installation.
Minor smoke and odor may be present
temporarily after start--up from the manufacturing process.
Some occupants are more sensitive to this minor smoke and
odor. It is recommended that doors and windows be open
during the first heat cycle.
NOTICE
INTRODUCTION
This 4--way multipoise Category IV condensing furnace is CSA
design--certified as a direct--vent (2-pipe) or non-direct vent
(1-pipe) furnace. The furnace is factory--shipped for use with
natural gas. The furnace can be converted in the field for use with
propane gas when a factory-supplied conversion kit is used. Refer
to the furnace rating plate for conversion kit information.
This furnace is not approved for installation in mobile homes,
recreational vehicles, or outdoors.
This furnace is designed for minimum continuous return--air
temperature of 60
_
F (15
_
C) db or intermittent operation down to
55
_
F (13
_
C) db such as when used with a night setback
thermostat. Return-air temperature must not exceed 80
_
F (27
_
C)
db. Failure to follow these return-air temperature limits may affect
reliability of heat exchangers, motors, and controls. See Fig. 3.
The furnace should be sized to provide 100 percent of the design
heating load requirement plus any margin that occurs because of
furnace model size capacity increments. None of the furnace
model sizes can be used if the heating load is 20,000 BTU or
lower. Use Air Conditioning Contractors of America (Manual J
and S); American Society of Heating, Refrigerating, and
Air-Conditioning Engineers; or other approved engineering
method to calculate heating load estimates and select the furnace.
Excessive oversizing of the furnace may cause the furnace and/or
vent to fail prematurely, customer discomfort and/or vent freezing.
Failure to follow these guidelines is considered faulty installation
and/or misapplication of the furnace; and resulting failure, damage,
or repairs may impact warranty coverage.
For accessory installation details, refer to the applicable instruction
literature.
NOTE
: Remove all shipping materials, loose parts bag, and
literature before operating the furnace. See
Table
2.
CODES AND STANDARDS
Follow all national and local codes and standards in addition
to these instructions.
The installation must comply with
regulations of the serving gas supplier, local building, heating,
plumbing, and other codes. In absence of local codes, the
installation must comply with the national codes listed below and
all authorities having jurisdiction.
In the United States and Canada, follow all codes and standards for
the following:
Safety
S
US: Current edition of National Fuel Gas Code (NFGC) NFPA
54/ANSI Z223.1 and the Installation Standards, Warm Air
Heating and Air Conditioning Systems ANSI/NFPA 90B
S
CANADA: Current edition of National Standard of Canada,
Natural Gas and Propane Installation Code (NSCNGPIC)
CAN/CSA B149.1
General Installation
S
US: NFGC and the NFPA 90B. For copies, contact the National
Fire Protection Association Inc., Batterymarch Park, Quincy,
MA 02269; or for only the NFGC contact the American Gas
Association, 400 N. Capitol, N.W., Washington DC 20001
S
CANADA: NSCNGPIC. For a copy, contact Standard Sales,
CSA International, 178 Rexdale Boulevard, Etobicoke
(Toronto), Ontario, M9W 1R3, Canada
Combustion and Ventilation Air
S
US: Section 9.3 of the current edition of NFPA54/ANSI Z223.1
Air for Combustion and Ventilation
S
CANADA: Part 8 of the current edition of CAN/CSA B149.1,
Venting Systems and Air Supply for Appliances
Duct Systems
S
US and CANADA: Current edition of Air Conditioning
Contractors Association (ACCA) Manual D, Sheet Metal and Air
Conditioning Contractors National Association (SMACNA), or
American Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE) Fundamentals Handbook Chapter 35
Acoustical Lining and Fibrous Glass Duct
S
US and CANADA: Current edition of SMACNA, NFPA 90B as
tested by UL Standard 181 for Class I Rigid Air Ducts
Gas Piping and Gas Pipe Pressure Testing
S
US: Current edition of NFPA 54/ANSI Z223.1 NFGC; Chapters
5, 6, 7, and 8 and national plumbing codes.
CANADA: Current edition of CAN/CSA--B149.1, Parts 4, 5, 6,
and 9.