Install Condensate Drain; Duct System - Lennox CBX25UH Installation Instructions Manual

INSTALL CONDENSATE DRAIN

The air handler is equipped with ¾" NPT condensate drain
connections.
IMPORTANT
On some pans, the primary and secondary drain holes
have knockouts.
Confirm primary and secondary drains are open.
1. CBX25UH units are equipped with a drain pan, which
includes green (main drain) and red (secondary drain)
plugs. Unscrew the plugs to remove them before
inserting condensate drain fittings.
ALL CBX25UH MODELS
UNSCREW PLUGS
AND CONNECT
PROPERLY SIZED
FIELD-PROVIDED
FITTINGS AND
DRAIN LINES.
GREEN MAIN
DRAIN PAN
DRAIN PLUG
Figure 12. Drain Line Connections
2. Install properly sized, field-provided connection
fittings and connect primary drain line to the main drain
pan connection.
NOTE - When installing drain line connection fittings to
the drain pan, hand tighten the fitting and use a thread
sealant. Over-tightening
connections on the drain pan.
3. If the secondary drain line is to be used, remove the
plug or the knockout and route the drain line so that
water draining from the outlet will be easily noticed by
the homeowner. Refer to local codes for drain trap
requirements on the secondary drain line.
4. Check again to ensure drain ports and drain pan are
free of all debris.
5. Plug and check any unused drain pan openings for
tightness. Torque plugs to 30 in. lb. to prevent water
leaks or seepage from the drain pan.
6. Install a 2" trap in the main (primary) drain lines as
close to the unit as practical (see figure 10). Make sure
the top of the trap is below the connection to the drain
pan to allow complete drainage of the pan.
RED SECONDARY
DRAIN PLUG
the fittings can split
NOTE - Horizontal runs must have an anti-siphon air
vent (standpipe) installed ahead of the horizontal run.
See figure 10. An extremely long horizontal run may
require an oversized drain line to eliminate air traps.
NOTE - Do not operate air handler without a trap in the
main (primary) drain. The condensate drain is on the
negative pressure side of the blower; therefore, air
being pulled through the condensate line will not allow
positive drainage without a proper trap.
7. Route the drain line to the outside or to an appropriate
drain. Drain lines must be installed so they do not block
service access to the front of the air handler. A 24"
clearance is required for filter, coil, or blower removal
and service access.
NOTE - Check local codes before connecting the drain
line to an existing drainage system.
Insulate the drain lines where sweating could cause water
damage.
TEST CONDENSATE DRAIN
Test the drain pan and drain line after installation:
1. Pour several quarts of water into drain pan. Use
enough water to fill both the drain trap and the line.
2. Check the installed drain pan. Drain pan must be
draining completely. Drain line fittings must not be
leaking. Water must be draining from the end of the
primary drain line.
3. Correct any leaks found.
Duct System and Filters

DUCT SYSTEM

The air handler is provided with flanges for the connection
of the supply plenum.
Supply and return duct system must be adequately sized
to meet the system's air requirements and static pressure
capabilities. The duct system should be insulated with a
minimum of 1" thick insulation with a vapor barrier in
conditioned areas or 2" minimum in unconditioned areas.
Supply plenum should be the same size as the flanged
opening provided around the blower outlet and should
extend at least 3 ft. from the air handler before turning or
branching off plenum into duct runs. The plenum forms an
extension of the blower housing and minimizes air
expansion losses from the blower.
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