Lennox MERIT Series Installation Instructions Manual page 31

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
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.
5' max.
to drain
Drain
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
Optional
Page 31
FIGURE 47
HorizontalFurnace4" Min. to 5" Max.above
condensatedrain connection)
FurnaceCondensate
DrainConnection
FIGURE 48