F97CMN and G97CMN: 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.
12
A14532
Fig. 12 – Example of Field Drain Attachment (Not Allowed)
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-in. (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. 13 – Formed Rubber Drain Grommet
+
+
+
Condensing
Furnace
-
-
-
-
-
Evaporator Coil
+ +
+
< +
< +
< +
+
Blower
-
+
= Positive pressure
< +
= Pressure lower than areas with
+
−
= Negative pressure
Blower creates positive pressure.
Positive pressure extends into coil
condensate drain (no trap).
Furnace condensate does not flow
consistently when drain is at positive
pressure.
+
DIRECT
ION
OF
AI
RF
L
O
W
+
+
+
+
+
+
+
+
+
+
Condensing
Furnace
-
-
- -
-
Evaporator Coil
+
+
+
< +
< +
< +
+
Blower
-
3/4” PVC
1/2
3/4
1/2” CPVC or larger*
+
= Positive pressure
< +
= Pressure lower than areas with
+
−
= Negative pressure
+
3/4” PVC
DIRECT
ION
OF
AI
RF
L
O
W
+
+
+
+
1/2
3/4
3/4
3/4
Open
standpipe
+
+
3/4
+
+
+
+
Condensing
Furnace
-
-
- -
-
Evaporator Coil
+
+
+
< +
< +
< +
+
Blower
-
3/4” PVC
3/4
1/2” CPVC or larger*
+
= Positive pressure
< +
= Pressure lower than areas with
+
−
= Negative pressure
+
3/4” PVC
DIRECT
ION
OF
AI
RF
L
O
W
+
+
+
+
3/4
3/4
3/4
3/4
3/4
+
+
+
+
+
+
+
+
+
+
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
