NOTE:
A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
VENTING
The 58MSA Furnaces require a dedicated, (one 58MSA furnace
only) sealed vent system. All air for combustion is taken from the
area adjacent to furnace, and all flue gases are discharged to
outdoor atmosphere.
Step 1—Removal of Existing Furnaces from
Common Vent Systems
When an existing Category I furnace is removed or replaced, the
original venting system may no longer be sized to properly vent
the remaining attached appliances. An improperly sized Category
I venting system could cause the formation of condensate in the
furnace and vent, leakage of condensate and combustion products,
spillage of combustion products into the living space, etc.
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance
connected to the venting system being placed into operation
could result in carbon monoxide poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into operation,
while all other appliances connected to the venting system are
not in operation:
1. Seal any unused openings in venting system.
2. Inspect the venting system for proper size and horizontal
pitch, as required in the National Fuel Gas Code, ANSI
Z223.1-2002/NFPA 54-2002 or the CSA B149.1, Natural
Gas and Propane Installation Code and these instructions.
Determine that there is no blockage or restriction, leakage,
corrosion and other deficiencies, which could cause an
unsafe condition.
3. As far as practical, close all building doors and windows
and all doors between the space in which the appliance(s)
connected to the venting system are located and other
spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected to
the venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they are operating
at maximum speed. Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance being
inspected into operation. Adjust the thermostat so appli-
ance is operating continuously.
7. Test for spillage from draft hood equipped appliances at the
draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle.
8. If improper venting is observed during any of the above
tests, the venting system must be corrected in accordance
with the National Fuel Gas Code, ANSI Z223.1-
2002/NFPA 54-2002 and/or CSA B149.1, Natural Gas and
Propane Installation Code.
9. After it has been determined that each appliance connected
to the venting system properly vents when tested as
outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas-fired appliance to their
previous conditions of use.
Vent system or vent connectors may need to be resized. For any
other appliances when resizing vent systems or vent connectors,
system or connector must be sized to approach minimum size as
determined using appropriate table found in the NFGC or NSC-
NGPIC.
Step 2—Combustion-Air and Vent Piping
GENERAL
Solvent cements are combustible. Keep away from heat,
sparks, and open flame. Use only in well-ventilated areas.
Avoid breathing in vapor or allowing contact with skin or
eyes. Failure to follow this warning could result in fire,
property damage, personal injury, or death.
Combustion-air and vent pipe, fittings, primers, and solvents must
conform to American National Standards Institute (ANSI) stan-
dards and American Society for Testing and Materials (ASTM)
standards. See Table 5 for approved materials for use in the U.S.A.
See Table 6 for maximum pipe lengths and Fig. 39, 40, and 41 for
exterior piping arrangements.
In Canada, construct all combustion-air and vent pipes for this unit
of CSA or ULC listed schedule-40 PVC, PVC-DWV or ABS-
DWV pipe and pipe cement. SDR pipe is NOT approved in
Canada.
Vent pipe termination must be installed with adequate clearances
to building openings and equipment to comply with national and
local codes. See Table 8 for required clearances.
COMBUSTION AIR PIPE
Combustion air must not be taken from inside a structure that
is frequently contaminated by halogens, which include fluo-
rides, 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.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.
NOTE:
Furnace combustion-air connections are sized for 2-in.
pipe. The combustion-air pipe will be 2-in. diameter in all
installations.
Furnace combustion-air connection must be attached as shown in
Fig. 34. Combustion-air intake housing plug may need to be
relocated in some applications.
Combustion-air pipe must terminate outside of furnace casing with
1 elbow. Orient elbow so that opening faces down for upflow or
downflow applications. Orient elbow so that it faces sideways (left
or right) for horizontal left or horizontal right applications. (See
Fig. 34.) Maintain a 3-in. minimum clearance between the opening
of the combustion-air inlet pipe and any object.
NOTE:
All pipe joints must be cemented except attachment of
combustion-air inlet pipe to inlet housing connection, since it may
be necessary to remove pipe for servicing.
Install combustion air inlet pipe as follows:
1. Assemble combustion-air inlet pipe.
a. Permanently install perforated disk assembly (factory-
supplied in loose parts bag) in combustion-air elbow using
RTV or by cementing. (See Fig. 35.)
For 120,000 Btuh size units only: Separate the 2 halves of
perforated disk assembly and use only the shouldered disk
half.
b. Determine length of straight portion of combustion-air inlet
pipe from table in Fig. 35.
c. Cut field-supplied 2-in diameter PVC pipe to determined
length.
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