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Refer to gures 46 and 48 for condensate trap locations. 
Figure 54 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, eld-provided ttings and 
length of PVC pipe required to reach available drain.
2 -  Use  a  large  at  head  screw  driver  or  a  1/2”  drive 
socket extension  and remove plug  (gure 46)  from 
the cold end header box at the appropriate location 
on the side of the unit. Install provided 3/4 NPT street 
elbow  tting  into  cold  end  header  box.  Use  Teon 
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 54.
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 46   
4 -  Install  drain  trap  using  appropriate  PVC  ttings, 
glue all joints. Glue the provided drain trap as 
shown in Figure 54. Route the condensate line to 
an open drain. Condensate line must maintain a 1/4” 
downward slope from the furnace to the drain.
5 -  Figure 49 and Figure 51 shows the furnace and 
evaporator coil using a separate drain. If necessary 
the condensate line from the furnace and evaporator 
coil can drain together. See Figure 50, Figure 52, 
and Figure 53. Upow  furnace  (Figure  52)  - In 
upow  furnace  applications  the  eld  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  ooded  heat 
exchanger if the combined primary drain line were to 
become restricted. Horizontal furnace (Figure 53) 
- In horizontal furnace applications the eld 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  ooded  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  t-
ting may be used for condensate drain. Attach to the 
drain on the trap using a hose clamp. See Figure 47.
 CAUTION
Do not use copper tubing or existing copper condensate
lines for drain line.
Field Provided Drain Components
Tubing
Hose Clamp
Barbed Fitting
Elbow
Figure 47   
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 
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.