Install Instructions
Table Of Contents
- Safety Considerations
- Electrostatic Discharge (ESD) Precautions
- To The Installer
- Product Application
- Location Requirements & Considerations
- Clearances and Accessibility
- Combustion & Ventilation Requirements
- Installation Positions
- Horizontal Applications & Considerations
- Vent Pipe & Combustion Air Pipe
- Materials – Installations In The U.S.A.
- Materials – Installations In Canada
- Pipe Installation
- Combustion Air Pipe Connection
- Vent/Intake Terminations For Installation of Multiple Direct Vent Furnaces
- Condensate Drain Lines & Drain Trap
- General Drain Information
- Field Supplied Drain
- Upflow Model Installed Vertically
- Drain Exiting Right Side
- Drain Exiting Left Side
- Upflow Model Installed Horizontally with Right Side Down
- Upflow Model Installed Horizontally with Left Side Down
- Upflow Model Installed Horizontally With Left Side Down - Alternate
- CounterFlow Model Installed Vertically
- Drain Exiting Left Side (See Figure 28)
- Drain Exiting Right Side (See Figure 29)
- Counterflow Model Installed Horizontally with Right Side Down (See Figure 30)
- Counterflow Model Installed Horizontally with Left Side Down (See Figure 31)
- Electrical Connections
- Gas Supply and Piping
- High Altitude Installation
- Circulating Air & Filters
- Filters - Read This Section Before Installing The Return Air Duct work
- Startup Procedure & Adjustment
- Gas Supply Pressure Measurement
- Operational Checks
- Safety Circuit Description
- Maintenance
- Filters
- Before Leaving an Installation
- Repair and Replacement Parts
- Special Instructions for Products Installed in the State of Massachusetts
33
CUT FOUR CORNERS
AFTER REMOVING SHEET
METAL
CUT USING TIN SNIPS
PRESS OUT BY HAND
SCRIBE LINES OUTLINING
DUCT FLANGES
When the furnace is used in connection with a cooling unit,
the furnace should be installed in parallel with or on the
upstream side of the cooling unit to avoid condensa tion
in the heating element. With a parallel ow arrange ment,
the dampers or other means used to control the ow of
air must be adequate to prevent chilled air from entering
the furnace and, if manually operated, must be equipped
with means to prevent operation of either unit unless the
damper is in the full heat or cool position.
When the furnace is installed without a cooling coil, it is
recommended that a removable access panel be provided
in the outlet air duct. This opening shall be accessible
when the furnace is installed and shall be of such a size
that the heat exchanger can be viewed for visual light
inspection or such that a sampling probe can be inserted
into the air stream. The access panel must be made to
prevent air leaks when the furnace is in operation.
When the furnace is heating, the temperature of the return
air entering the furnace must be between 55°F and 100°F.
Filters must be used with this furnace. Discuss lter
maintenance with the building owner. Filters do not ship
with this furnace, but must be provided, sized and installed
externally by the installer. Filters must comply with UL900
or CAN/ULCS111 standards. Damage or repairs due to
the installation of the furnace without lters is not covered
under the warranty.
On upow units, guide dimples locate the side return
cutout locations. Use a straight edge to scribe lines
connecting the dimples. Cut out the opening on these
lines. NOTE: An undersized opening will cause reduced
airow.
Refer to the Filter Sizing Chart to determine lter area
requirements.
Model
1 - 16 X 25 Side or 1 - 14 X 24 Bottom Return
1 - 16 X 25 Side or Bottom Return
1 - 16 X 25 Side or Bottom Return
1 - 16 X 25 Side or Bottom Return
2 - 16 X 25 Side or 1 - 20 X 25 Bottom Return
2 - 16 X 25 Side or 1 - 20 X 25 Bottom Return¹
2 - 16 X 25 Side or 1 - 24 X 24 Bottom Return¹
2 - 10 X 20 or 1 - 14 X 25 Top Return
2 - 10 X 20 or 1 - 14 X 25 Top Return
2 - 14 X 20 or 1 - 16 X 25 Top Return
2 - 14 X 20 or 1 - 20 X 25 Top Return
2 - 14 X 20 or 1 - 24 X 24 Top Return
Larger filters may be used, filters may also be centrally located.
¹ = use 2 - 16 X 25 filters and two side returns or 20 X 25 filter on
bottom return or combination side & bottom if furnace is connected to
a cooling unit over 4 tons nominal capacity
Model
*M9S920403AN 1 - 16 X 25 Side or 1 - 14 X 24 Bottom Return
1 - 16 X 25 Side or Bottom Return
*M9S920803BN 1 - 16 X 25 Side or Bottom Return
*M9S920804CN 1 - 16 X 25 Side or Bottom Return
*M9S920805CN 2 - 16 X 25 Side or 1 - 20 X 25 Bottom Return
*M9S921004CN 1 - 16 X 25 Side or Bottom Return
*M9S921005CN 2 - 16 X 25 Side or 1 - 20 X 25 Bottom Return¹
2 - 16 X 25 Side or 1 - 24 X 24 Bottom Return¹
Larger filters may be used, filters may also be centrally located.
¹ = use 2 - 16 X 25 filters and two side returns or 20 X 25 filter on
bottom return or combination side & bottom if furnace is
connected to a cooling unit over 4 tons nominal capacity
Consider installing an air cleaner with deep-pleated media
lter at the time of furnace installation. A deep-pleated
lter with a MERV rating of 8 (minimum) will often provide
better ltration to protect equipment and the air distribution
system than a standard 1” lter and often has lower static
pressure loss than a 1” lter. Also a deep-pleated lter
will typically require less frequent replacement intervals.
Avoid using highly restrictive 1” lters which produce static
pressure loss greater than .25” W.C. In some installations
the minimum lter size required (consult lter sizing chart
above) will not lend itself to a lter installation on the side
of the furnace. The installation of a centrally installed air
cleaner cabinet or a return duct lter installation may oer
more practicality.