Page 35
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.
NOTE -
Do not remove the rubber grommet used to
seal the cabinet on the side not used when installing
the condensate trap.
2 - Use a large flat head screw driver or a 1/2” drive socket
extension and remove plug (figure 44) 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 appropri
ate pipe dope.
NOTE -
Cold end header box drain plugs are factory in
stalled. Check the unused plug for tightness to prevent
leakage.
3 - Install the cap over the clean out opening at the base
of the trap. Secure with clamp. See figure 52.
4 - Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in fig
ure 52. Route the condensate line to an open drain.
Condensate line must maintain a 1/4” downward slope
from the furnace to the drain.
FIGURE 44
CONDENSATE TRAP AND PLUG LOCATIONS
(Unit shown in upflow position)
NOTE - In up flow applications where side re
turn air filter is installed on same side as the
condensate trap, filter rack must be installed
beyond condensate trap or trap must be re-lo
cated to avoid interference.
Trap
(same on
right side)
Plug
(same on left side)
1-1/2 in.
Rubber
Grommet
5 - Figures 47 and 49 show the furnace and evaporator
coil using a separate drain. If necessary the conden
sate line from the furnace and evaporator coil can
drain together. See figures 48, 50 and 51.
Upflow furnace (figure 50)
- In upflow furnace applica
tions the field provided vent must be a minimum 1” to a
maximum 2” length above the condensate drain outlet
connection. Any length above 2” may result in a flood
ed heat exchanger if the combined primary drain line
were to become restricted.
Horizontal furnace (figure 51)
- In horizontal furnace
applications the field provided vent must be a mini
mum 4” to a maximum 5” length above the condensate
drain outlet connection. Any length above 5” may re
sult in a flooded heat exchanger if the combined pri
mary drain line were to become restricted.
NOTE -
In horizontal applications it is recommended to
install a secondary drain pan underneath the unit and
trap assembly.
NOTE
- Appropriately sized tubing and barbed fitting
may be used for condensate drain. Attach to the drain
on the trap using a hose clamp. See figure 45.
6 - If unit will be started immediately upon completion of in
stallation, prime trap per procedure outlined in Unit Start-
Up section.
FIGURE 45
Tubing
Hose Clamp
Barbed Fitting
Field Provided Drain Components
Elbow
CAUTION
Do
not use copper tubing or existing copper conden
sate lines for drain line.
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. Heating cable kit is
available from Lennox in various lengths; 6 ft. (1.8m) -
kit no. 26K68 and 24 ft. (7.3m) - kit no. 26K69.
