Lennox MERIT Series Installation Instructions Manual page 29

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. 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.
CONDENSATE TRAP LOCATION
(shown with right side exit of condensation)
Trap can be installed a maximum
of 5ft. from furnace (*PVC only)
Field Provided Vent
1" min. 2" max. above
condensate drain.
1" min.
2" max .
*Piping from furnace must slope down a
minimum 1/4" per ft. toward trap
FIGURE 45
Furnace with Evaporator Coil
Using a Separate Drain
Field Provided Vent
1" min. 2" max. above
condensate drain.
Condensate
Drain Connection
Evaporator Drain Line
(vent required)
FIGURE 46
5' max.
to drain
When combining the furnace and evaporator coil
drains together, the A/C condensate drain outlet must
be vented to relieve pressure in order for the furnace
pressure switch to operate properly.
Do not use copper tubing or existing copper condensate
lines for drain line.
Furnace with Evaporator
Coil Using a Common Drain
Field Provided Vent
1" min. 2" max. above
condensate drain.
Condensate
Drain Connection
Evaporator Drain Line
(vent required)
Condensate Trap With Optional Overflow Switch
From Evaporator Coil
Drain
Page 29
IMPORTANT
IMPORTANT
FIGURE 47
HorizontalFurnace4" Min. to 5" Max.above
condensatedrain connection)
FurnaceCondensate
DrainConnection
Optional
FIGURE 48