Lennox MERIT Series Installation Instructions Manual page 30

Condensate Piping
This unit is designed for either right- or left-side exit of
condensate piping. Refer to figures 43 and 45 for conden-
sate trap locations.
NOTE - Do not remove the rubber grommet used to seal
the cabinet on the side not used when installing the con-
densate trap.
CONDENSATE TRAP AND PLUG LOCATIONS
Trap
(same on
right side)
1-1/2 in.
FIGURE 43
1 - Determine which side condensate piping will exit
the unit, location of trap, field-provided fittings and
length of PVC pipe required to reach available drain.
2 - Use a large flat head screw driver or a 1/2" drive
socket extension and remove plug (figure 43) from
the cold end header box at the appropriate location
on the side of the unit. Install provided 3/4 NPT street
elbow fitting into cold end header box. Use Teflon
tape or appropriate pipe dope.
NOTE - Cold end header box drain plugs are facto-
ry installed. Check the unused plug for tightness to
prevent leakage.
3 - Install the cap over the clean out opening at the base
of the trap. See figure 49.
4 - Install drain trap using appropriate PVC fittings, glue
5 - Figure 46 shows the furnace and evaporator coil
Do not use copper tubing or existing copper condensate
lines for drain line.
Plug
(same on left
side)
Rubber
Grommet
6 - If unit will be started immediately upon completion of
Condensate line must slope downward away from the
trap to drain. If drain level is above condensate trap,
condensate pump must be used. Condensate drain
line should be routed within the conditioned space to
avoid freezing of condensate and blockage of drain
line. If this is not possible, a heat cable kit may be used
on the condensate trap and line. Heat cable kit is avail-
able from Lennox in various lengths; 6 ft. (1.8m) - kit
no. 26K68 and 24 ft. (7.3m) - kit no. 26K69.
Page 30
all joints. Glue the provided drain trap as shown in
figure 49. Route the condensate line to an open
drain.
NOTE - If necessary the condensate trap may be
installed up to 5 feet away from the furnace. Piping
from furnace must slope down a minimum of 1/4"
per ft. toward trap.
NOTE - Appropriately sized tubing and barbed fit-
ting may be used for condensate drain. Attach to the
drain on the trap using a hose clamp. See figure 44.
using a separate drain. If necessary, the condensate
line from the furnace and evaporator coil can drain
together. See figures 47 and 48. The field provided
vent must be a minimum 1" to a maximum 2" length
above the condensate drain outlet connection.
CAUTION
Field Provided Drain Components
Elbow
Tubing
FIGURE 44
installation, prime trap per procedure outlined in Unit
Start-Up section.
Barbed Fitting
Hose Clamp