INSTALLATION CONSIDERATIONS
21
Condensate Drain Lines and Drain Trap
A condensing gas furnace achieves its high level of efficiency
by extracting almost all of the heat from the products of com
-
bustion and cooling them to the point where condensation
takes place. The condensate which is generated must be
piped to an appropriate drain location.
WARNING
I
N UPRIGHT UPFLOW INSTALLATIONS, THE DRAIN TRAP MUST BE MOUNTED ON
THE OPPOSITE SIDE OF THE UNIT FROM THE JUNCTION BOX.
T
HIS WILL
REDUCE THE RISK OF WATER REACHING THE JUNCTION BOX IN THE EVENT OF
A BLOCKED DRAIN CONDITION.
F
AILURE TO FOLLOW THESE INSTRUCTIONS
CAN RESULT IN POSSIBLE PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH
DUE TO ELECTRICAL SHOCK.
•
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.
Drain Information for Horizontal Installations
NOTE:
Horizontal installations require 5.5" under the furnace
to accommodate the drain trap. The horizontal furnace must be
installed with ¾" slope from back to front to permit condensate
flow towards the front of the furnace.
When installing a DM92SE horizontally with the left side
down, there are two options for connecting the vent pipe to
the furnace.
Option 1
Venting may be connected to the furnace vent pipe fitting on
the original top (now the end) of the furnace.
Option 2
The internal vent pipe and elbow may be removed from the
furnace to permit the vent to exit the top (original side) of
the furnace. If this option is used, an RF000142 Vent-Drain
coupling must be used to keep condensate from collecting in
the inducer assembly.
To install the drain, refer to the following instructions and
illustration.
COMBUSTION AIR INTAKE PIPE OPTIONS:
The RF000142 coupling can be secured directly to the
furnace intake coupling if condensation is occurring in the
combustion air inlet pipe. If the RF000142 is used on the
combustion air inlet, it must be installed with the arrow
pointing up. It should be noted, the combustion air will
actually be moving in a direction opposite of the arrow on the
RF000142 coupling.
Alternatively a tee may be used in the combustion air in
-
take pipe for the same purpose. If either option is used, a
field supplied trapped drain tube, free-draining to proper
condensate disposal location must be present. A loop in the
drain tube can serve as a trap. The unused RF000142 drain
fitting should be capped.
1. Remove screws from vent flange.
2. Remove internal elbow and vent pipe.
3. Cut pipe 2 1/2" from flange.
4. Remove cabinet plug adjacent to inducer outlet and in
-
stall an original cabinet vent hole.
5. Install RF000142 coupling on inducer outlet.
6. Install flanged vent section removed in step 2 and se
-
cure with clamps.
7. Secure flange to cabinet using screws removed in step
1.
Insert flange. Cut 2 ½” long.
R 000142
F
