Lennox ELITE Series Installation Instructions Manual page 33

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 51
IMPORTANT
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.
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)
FIGURE 52
Condensate Trap With Optional Overflow Switch
From Evaporator Coil
Optional
Drain
Do not use copper tubing or existing copper condensate
lines for drain line.
Page 33
HorizontalFurnace4" Min. to 5" Max.above
condensatedrain connection)
FurnaceCondensate
DrainConnection
FIGURE 53
CAUTION