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• The drain line between furnace and drain location
must maintain a 1/4 inch per foot downward slope
toward the drain.
•
Do not trap the drain line in any other location than at
the drain trap supplied with the furnace.
• If the drain line is routed through an area which may
see temperatures near or below freezing, precautions
must be taken to prevent condensate from freezing
within the drain line.
• If an air conditioning coil is installed with the furnace,
a common drain may be used. An open tee must
be installed in the drain line, near the cooling coil, to
relieve positive air pressure from the coil’s plenum.
This is necessary to prohibit any interference with the
function of the furnace’s drain trap.
NOTE: In vertical installations, air conditioning
coil condensate may drain into the furnace trap
as long as there is a trap between the coil and the
furnace trap and the drain pipe is not terminating
below the water level of the furnace trap.
General Drain Information
All furnace models come with a factory installed drain trap.
For vertical installations, the trap will remain in the factory
position except for a counterflow when the installer desires
the drain to exit the right side. All furnace models installed
horizontally require the trap to be relocated. Many drain
hoses have a built–in grommet which will provide a cabinet
seal when installed. See instructions below for your model
and installation position.
NOTE: Both sides of the drain trap must be primed
prior to initial furnace start up
Field Supplied Drain
Drain the furnace and air conditioning coil if applicable,
in compliance with code requirements. In horizontal or
counterflow installations, a field installed rubber coupling
will allow the drain trap to be removed for cleaning. The
drain trap must be primed before initial furnace start up.
When an air conditioning coil drain is connected to the
field supplied furnace drain, it must be vented, with an
open tee installed at a height no higher than the bottom
of the furnace collector box to prevent air conditioning
condensate from backing up into the furnace if the common
drain was blocked.
Upflow Model Installed Vertically
The trap and factory installed hoses remain as shipped.
The furnace drain may exit either the right or left side of the
furnace cabinet. Both sides of the cabinet have two .875”
diameter holes which can be used interchangeably for
drain and low voltage wiring purposes. If a higher drain exit
is needed, a .875” diameter hole may be added in the area
shown in Figure 22. Any unused cabinet opening must be
sealed. Do not allow drain hose to sag or trap
water.
manufacturer:
1. The referenced “special venting system” instructions
shall be included with the appliance or equipment
installation instructions; and
2. The “special venting systems” shall be Product
Approved by the Board, and the instructions for
that system shall include a parts list and detailed
installation instructions.
e. A copy of all installation instructions for all
Product Approved side wall horizontally vented
gas fueled equipment, all venting instructions,
all parts lists for venting instructions, and/or all
venting design instructions shall remain with the
appliance or equipment at the completion of the
installation.
#3
#1
#2
#4
#5
#6
#7
#8
#9
#10
#11
100 Degree
Elbow
Coupling
Figure 22
NOTE: Drain componenets shown for information
purposes only.
CONDENSATE DRAIN LINES & DRAIN
TRAP
A condensing gas furnace achieves its high level
of efficiency by extracting heat from the products of
combustion to the point where condensation takes place.
The condensate must be collected in the furnace drain trap
and routed to an appropriate drain location in compliance
with local and national codes.
Follow the bullets listed below when installing the drain
system. Refer to the following sections for specific details
concerning furnace drain trap installation and drain hose
hook ups.
• The drain trap supplied with the furnace must be
used.
• The drain trap must be primed at time of installation.
• The drain line between furnace and drain location
must meet local and nation codes.
