Page 40
Condensate Piping
This unit is designed for either right- or left-side exit of
condensate piping in upflow applications. In horizontal
applications, the condensate trap must extend below the
unit. An 8” service clearance is required for the conden
-
sate trap. Refer to figure 41 for condensate trap locations.
Figure 49 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. Install provided
3/4 NPT street elbow fitting into cold end header
box. Use Teflon tape or appropriate pipe dope.
3 - Install the cap over the clean out opening at the
base of the trap. Secure with clamp. See figure 49.
4 - Install drain trap using appropriate PVC fittings,
glue all joints. Glue the provided drain trap as
shown in figures 49. Route the condensate line to
an open drain. Condensate line must maintain a
1/4” downward slope from the furnace to the drain.
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.
Rubber
Grommet
FIGURE 41
5 - Figures 44 and 46 show the furnace and evaporator
coil using a separate drain. If necessary the
condensate line from the furnace and evaporator
coil can drain together. See figures, 45, 47 and 48.
Upflow furnace (figure 47) -
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 48) -
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 fitting
may be used for condensate drain. Attach to the
drain on the trap using a hose clamp. See figure 42.
Field Provided Drain Components
Tubing
Hose Clamp
Barbed Fitting
Elbow
FIGURE 42
CAUTION
Do not use copper tubing or existing copper
condensate lines for drain line.
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 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 Page 41 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.
