American Standard CUX1B040A9241A Installation, Operation And Maintenance Manual page 23

Downflow furnace - The furnace is shipped with the left side
drainage setup. To change the right side drain, remove the drain
lines from the trap, rotate the trap 180° so it exits to the right,
reconnect the lines, and run a 1/2" CPVC pipe from the trap out
through the right side knock-out. Use RTV silicone sealant to
connect the CPVC pipe to the trap for ease of removing to clean
the trap.
HORIZONTAL APPLICATIONS
Upflow and Downflow furnaces - All horizontal applications
are left side only. It is always recommended that the auxiliary
drain pan be installed under a horizontally installed evaporator
and/or 90% gas furnace. Connect the auxiliary drain pan to a
separate drain line (no trap is needed in this line).
Left side
UPFLOW (VERTICAL)
UPFLOW HORIZONTAL 21" & 24" UNITS
(Left side only)
Pub. No. 41-5016-12
The trap must be repositioned to the exterior of the cabinet. Remove
the trap from its present location and reposition the trap outside
of the unit, through the long circular hole, next to the secondary
recuperative cell. Remove the larger drain line (from the secondary
cell) and trim to fit between the secondary cell and the new trap
location. On upflow units, plug the hole in the blower deck where the
tube went through.
Remove the hose from the induced blower and reposition into the
other drain tap of the inducer, which is located 90° clockwise around
the inducer. Move the cap from that drain tap to the unused drain
tap. On upflow units, plug the hole in the blower deck where the tube
went through. This tube on downflow units will need to be cut to fit
between the inducer and the trap. On upflow units, this tube may
need to be extended, using the tubing shipped with the furnace.
Left
side
Use
extension
hose here
Installation Instructions
DOWNFLOW (VERTICAL)
Use CPVC tubing from Trap outlet,
over burner box to cabinet exit
DOWNFLOW (VERTICAL)
Right
side
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