507762-01
Issue 1907
Page 30 of 46
Condensate Piping
This unit is designed for either right- or left-side exit of
condensate piping in upflow applications. In horizontal
applications, the condensate trap must extend below the
unit. An 8” service clearance is required for the condensate
trap.
Refer to Figure 47 and Figure 49 for condensate trap
locations. Figure 55 shows trap assembly using 1/2” PVC
or 3/4” PVC.
NOTE:
If necessary the condensate trap may be installed
up to 5’ away from the furnace. Use PVC pipe to connect
trap to furnace condensate outlet. Piping from furnace
must slope down a minimum of 1/4” per ft. toward trap.
1. Determine which side condensate piping will exit the
unit, location of trap, field-provided fittings and length
of PVC pipe required to reach available drain.
2. Use a large flat head screw driver or a 1/2” drive
socket extension and remove plug (Figure 47) from
the cold end header box at the appropriate location
on the side of the unit. Install provided 3/4 NPT street
elbow fitting into cold end header box. Use Teflon tape
or appropriate pipe dope.
NOTE:
Cold end header box drain plugs are factory
installed. Check the unused plug for tightness to
prevent leakage.
3. Install the cap over the clean out opening at the base
of the trap. Secure with clamp. See Figure 55.
(Unit shown in upflow position)
Trap
(same on
right side)
Plug
(same on
left side)
1-1/2 in.
NOTE -
In upflow applications where side return air filter is
installed on same side as the condensate trap, filter rack must
be installed beyond condensate trap or trap must be relocated
to avoid interference.
Figure 47. Condensate Trap and Plug Locations
4. Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in
Figure 55. Route the condensate line to an open drain.
Condensate line must maintain a 1/4” downward slope
from the furnace to the drain.
5. Figure 51 and Figure 53 show the furnace and
evaporator coil using a separate drain. If necessary
the condensate line from the furnace and evaporator
coil can drain together. See Figure 50, Figure 52 and
Upflow furnace (Figure 52) -
In upflow furnace
applications the field provided vent must be a minimum
1” to a maximum 2” length above the condensate drain
outlet connection. Any length above 2” may result in a
flooded heat exchanger if the combined primary drain
line were to become restricted.
Horizontal furnace (Figure 54) -
In horizontal furnace
applications the field provided vent must be a minimum
4” to a maximum 5” length above the condensate drain
outlet connection. Any length above 5” may result in a
flooded heat exchanger if the combined primary drain
line were to become restricted.
NOTE:
In horizontal applications it is recommended to
install a secondary drain pan underneath the unit and
trap assembly.
NOTE:
Appropriately sized tubing and barbed fitting
may be used for condensate drain. Attach to the drain
on the trap using a hose clamp. See Figure 48.
Do not use copper tubing or existing copper condensate
lines for drain line.
CAUTION
Tubing
Hose Clamp
Barbed Fitting
Elbow
Figure 48. Field-Provided Drain Components
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. Heating cable kit is
available from Allied Air in various lengths; 6 ft. (1.8m)
- kit no. 26K68 and 24 ft. (7.3m) - kit no. 26K69.
