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Furnace with Evaporator
Coil Using a Common Drain
(1” min. to 2” Max.above
condensatedrain connection)
Condensate
DrainConnection
Evaporator drain
line required
(Trap at coil is optional)
FIGURE 49
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
(Unit shown in horizontal left−hand discharge position)
Condensate Drain
Connection
(4” min. to 5” Max.above
condensatedrain connection)
5’ max.
PVC Pipe Only
4”min
5”max
Evaporator
Coil
Drain Pan
Piping from furnace and evaporator coil must slope
down a minimum 1/4” per ft. toward trap
(Trap at coil is optional)
FIGURE 50