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Refer to figures 47 and 49 for condensate trap locations.
Figure 55 shows trap assembly using 1/2” PVC or 3/4”
PVC.
NOTE - If necessary the condensate trap may be installed
up to 5’ away from the furnace. Use PVC pipe to connect
trap to furnace condensate outlet. Piping from furnace
must slope down a minimum of 1/4” per ft. toward trap.
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 47) 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. Secure with clamp. See figure 55.
CONDENSATE TRAP AND PLUG LOCATIONS
(Unit shown in upflow position)
NOTE - In upflow applications where side return
sate trap, filter rack must be installed beyond
condensate trap or trap must be re-located to
avoid interference.
Trap
(same on
right side)
Plug
(same on left side)
1-1/2 in.
Figure 47
4 - Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in
figure 55. Route the condensate line to an open drain.
Condensate line must maintain a 1/4” downward
slope from the furnace to the drain.
5 - Figures 50 and 52 show the furnace and evaporator oil
using a separate drain. If necessary the condensate
line from the furnace and evaporator coil can drain
together. See figures 51, 53 and 54.
Upflow furnace
(figure 53)
- In upflow furnace applications 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 flooded heat
exchanger if the combined primary drain line were
to become restricted.
Horizontal furnace (figure 54)
- In horizontal furnace applications the field provided
vent must be a minimum 4” to a maximum 5” length
above the condensate drain outlet connection.
Any length above 5” may result in a flooded heat
exchanger if the combined primary 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 fit-
ting may be used for condensate drain. Attach to the
drain on the trap using a hose clamp. See figure 48.
IMPORTANT
Do not use copper tubing or existing copper condensate
lines for drain line.
Field Provided Drain Components
Tubing
Hose Clamp
Barbed Fitting
Elbow
Figure 48
6 - If unit will be started immediately upon completion of
installation, prime trap per procedure outlined in Unit
Start-Up section. Condensate line must slope down-
ward 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 con-
ditioned 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.
