915SB: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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from sagging or being dislocated from the furnace or termination point.
In the absence of local codes, consult the current edition of the National
Standard Plumbing Code, in the U.S. or the National Plumbing Code of
Canada in Canada.
Upflow/Downflow Orientation
In the Upflow or Downflow orientation, the condensate trap is inside the
furnace casing. The condensate drain must be routed from the trap
through the furnace casing. The condensate drain can be routed through
the left or right side of the casing. (The left or right side is as you are
viewing/facing the furnace from the front.)
An indoor coil condensate drain or humidifier drain can be connected to
the external furnace condensate drain provided:
• The drains are not hard piped together, and
• There is an air gap at the point where the two drain lines meet or
• All condensate piping is at least 3/4-in. PVC and there is a relief tee at
the top of condensate drain piping as shown in
NOTE:
On narrower casings, it may be easier to remove the condensate
trap, connect the drain line components and re-install the condensate
trap. Read the steps thoroughly to familiarize yourself with the required
steps.
For Right Side Condensate Drain:
1. Remove the 7/8-in. knock-out from the right side of the casing. See
for suggested knockout removal technique.
2. Remove the pre-formed rubber drain elbow and two spring clamps
from the loose parts bag.
3. Slide a spring clamp 1-inch (25 mm) down the plain end (the end
without the formed grommet) of the drain elbow.
4. From inside the casing, insert the formed grommet end of the elbow
through the 7/8-in. knockout in the casing.
5. Pull the grommet through the casing from the outside until it is
seated in the knockout
6. Attach the plain end of the drain elbow to the outlet stub on the
drain trap. Secure the drain elbow to the trap with the spring clamp.
A11342A
Fig. 14 – Formed Rubber Drain Grommet
L12F019B
Fig. 15 – Knockout Removal
The remaining drain line can be constructed from field supplied 1/2-in.
CPVC or 3/4-in. PVC pipe, in compliance with local building codes. A
factory-supplied 1/2-in. CPVC to 3/4-in. PVC adapter is supplied in the
loose parts bag for use as required.
7. Install the adapter or connect the 1/2-in. CPVC pipe by sliding a
spring clamp over the open end of the grommet on the outside the
furnace casing.
8. Open the spring clamp and insert the long end of the adapter or the
1/2-in. CPVC pipe into the outlet stub on the drain tube.
9. Connect additional condensate piping to a code-approved drain, or
to a condensate pump approved for use with acidic furnace
condensate and compatible with mineral and vegetable oils, such as
canola oil.
Allow at least 1/4-in. per foot (20 mm per meter) of slope down and
away from the furnace in horizontal sections of drain line.
TIP FROM CONTRACTORS:
Contractors have found that
temporarily removing the inducer assembly in upflow applications while
performing the steps, below, makes upflow left-side drain connections
easier.
For Left Side Condensate Drain Connection:
1. For left side condensate drainage, the drain line is routed from the
condensate trap, behind the inducer (upflow) or gas valve
(downflow) and out through the left side of the furnace casing. A
pre-formed 1/2-in. CPVC “Z-pipe” is provided with the furnace.
The Z-pipe is long enough to extend across the casing for drain
connections.
2. Locate the Z-pipe. Remove the pre-formed drain elbow and four
spring clamps from the loose parts bag.
3. The Z-pipe is connected to the condensate trap and the outside of
the furnace by modifying the formed rubber drain elbow as shown
.
4. Remove the formed grommet from the rubber drain elbow by
cutting the elbow along the vertical line located about 1-3/8 in. (35
mm) away from the formed grommet. See
. DO NOT
DISCARD THE FORMED GROMMET OR THE RUBBER
ELBOW. Both of these pieces will be used.
INSTALL CLAMPS ON DRAIN TUBE
ATTACH DRAIN TUBE TO CONDENSATE
DRAIN TRAP
PULL DRAIN STUB
THROUGH CASING
OPEN SPRING CLAMP
INSERT FACTORY
ï
SUPPLIED 1/2
ï
IN. CPVC
TO 3/4
ï
IN. PVC ADAPTER OR 1/2
ï
IN. CPVC PIPE
*CLAMP MAY BE LOCATED ON OUTSIDE OF DRAIN
TUBE
CAUTION
!
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and wear
appropriate protective clothing, safety glasses and gloves when
handling parts, and servicing furnaces.
