561276-UIM-C-0712
20
Johnson Controls Unitary Products
The condensate will flow to the drain better if an open stand pipe is
installed in the drain line. See Figure 24.
If evaporator coil or humidifier drains are combined with the furnace
drain, then the open stand pipe could be raised higher, above the 5”
minimum.
CONDENSATE DRAIN TERMINATION
A condensate sump pump MUST be used if required by local codes, or
if no indoor floor drain is available. The condensate sump pump must
be approved for use with acidic condensate.
FIGURE 24:
Typical. Condensate drain, vertical installation
A loop has been added to the pressure switch vacuum hose. How-
ever, ensure that all pressure switch hoses are routed such that
they prevent any condensate from entering the pressure switch.
It is possible for condensation to form inside the combustion air
(intake) pipe in the summer months if significant length of combus-
tion air pipe passes through conditioned space. This problem can
be averted by the addition of a simple drain tee, or a drain tee with a
drain on the combustion air pipe as close to the furnace as possi-
ble, as shown in Figure 25. This is true for all long horizontal vent-
ing in any furnace configuration. This will prevent the condensate
from entering the furnace.
To Open Or
Vented Drain
Tee
5” Min.
Open Stand Pipe
(Anti-siphon air vent)
NOTICE
FIGURE 25:
Typical. Combustion Pipe Drain Tee
DO NOT terminate the condensate drain in a chimney, or where the
drain line may freeze. If the drain line will be exposed to tempera-
tures below freezing, adequate measures must be taken to prevent
the drain line from freezing. Failure to provide proper protection
from freezing can result in improper operation or damage to the
equipment and possible property damage. When exposed to tem-
peratures below freezing, use of a 3 to 6 watt per foot at 115 VAC,
40°F (4.4°C) self-regulating, shielded and waterproof heat tape is
recommended on the drain line outside the furnace.
DO NOT trap the drain line at any other location than at the conden-
sate drain trap supplied with the furnace.
Liquid anti-freeze will cause damage to internal plastic parts of this
furnace. DO NOT attempt to winterize the furnace using liquid
anti-freeze.
Connect to Drain
Trap
Combustion Air Pipe
Tee with Drain Trap
Exhaust Pipe
