International comfort products C9MPX Installation Instructions Manual page 18

Condensate Drain Trap
This furnace removes both sensible and latent heat from the
products of combustion. Removal of the latent heat results in
condensation of the water vapor. The condensate is removed from
the furnace through the drains in the plastic transition and the vent
fitting. The drains connect to the externally mounted condensate
drain trap on the left or right side of the furnace.
The startup of a new furnace will involve a cycle or two of the
furnace to properly prime the condensate trap with water. Until the
trap is fully primed, some condensate will be pulled into the
combustion blower. The furnace may cycle on the pressure switch
connected to the plastic transition box due to condensate buildup.
After the trap is primed, the condensate will start draining from the
furnace. The combustion blower will clear out any remaining
condensate in the blower housing through the vent fitting
downstream of the blower. Note that the condensate trap can also
be primed by pouring water into the
1
Remove the / " (12.7mm) ID drain hose from either the gutter or
2
the white PVC tee trap. Using a funnel pour eight (8) ounces (257
1
ml) of water into / " ID drain hose. Water will flow through the drain
2
hose and into the condensate drain trap. This will prime both the
vent and the transition sides of the trap. Reconnect the
(12.7mm) ID drain hose to the original component, either the gutter
or the PVC tee trap.
The condensate drain trap supplied with the furnace MUST be
used. The drain connection on the condensate drain trap is sized
3
for / " PVC or CPVC pipe, however alternate
4
5
/ " (15.9mm) O.D.] or vinyl tubing with a minimum inner diameter
8
5
(I.D.) of / " (15.9mm) may also be used, as allowed by local
8
codes. Alternate drain pipes and hoses may be used as allowed by
local codes.
The drain line must maintain a
1
slope toward the drain. /
4
recommended. Installation of an overflow line is recommended
1
when the / " (19.1mm) per foot (304.8mm) slope to the
4
condensate drain cannot be maintained. A drain tube clip is
included in the furnace to prevent kinking/buckling of the drain
tube. The clip should remain in the furnace (between the door
switch plate and the blower shelf, Figure 10) during operation. See
Figure 20 for proper routing and installation of the overflow.
Figure 10 Drain Tube Clip Location
Drain Tube
Clip
Blower
Door
Shelf
Switch
Representative drawing only, some models may vary in appearance.
DO NOT trap the drain line in any other location than at the
condensate drain trap supplied with the furnace.
18
1
/ " (12.7mm) drain hose.
2
1
/ " CPVC [nominal
2
1
/ " (19.1mm) per foot downward
4
" (19.1mm) per foot (304.8mm) is
Specifications are subject to change without notice.
!
FROZEN AND BURST WATER PIPE HAZARD
Failure to follow this caution may result in property
damage.
If a condensate pump is installed, a plugged
condensate drain or a failed pump may cause the
furnace to shut down. Do not leave the home
unattended during freezing weather without turning
off water supply and draining water pipes or
otherwise protecting against the risk of frozen pipes.
If possible, DO NOT route the drain line where it may freeze. The
drain line must terminate at an inside drain to prevent freezing of
the condensate and possible property damage.
1. A condensate sump pump MUST be used if required by
local codes, or if no indoor floor drain is available. The
condensate pump must be approved for use with acidic
condensate.
1
/ "
2 2. A plugged condensate drain line or a failed condensate
pump will allow condensate to spill. If the furnace is installed
where a condensate spill could cause damage, it is
recommended that an auxiliary safety switch be installed to
prevent operation of the equipment in the event of pump
failure or plugged drain line. If used, an auxiliary safety
switch should be installed in the R circuit (low voltage)
ONLY.
3. If the auxiliary switch in the condensate pump is used, the
furnace may shut down due to a blocked condensate line or
failed pump. To prevent frozen water pipes see the "Frozen
Water Pipe Hazard" Installation Section of this manual.
Condensate Drain Trap Freeze Protection
Special precautions MUST be made if installing furnace in an area
which may drop below freezing. This can cause improper
operation or damage to the equipment. If the the furnace
environment has the potential of freezing, the drain trap and drain
line must be protected. Use 3 to 6 watt per foot at 115 volt, 40° F
self−regulating shielded and waterproof heat tape. Wrap the drain
trap and drain line with the heat tape and secure with the ties.
Follow the heat tape manufacturer's recommendations.
CAUTION
440 01 1051 02