Installation manual

7.3 Condensate Drain
System
The installer must provide a condensate drain system. A 4” PVC cleanout cap
(FIGURE 22) that is drilled and tapped for a 1/2” NPT tting is furnished with the
heater for the vent drain. All other material must be eld supplied.
During operation, condensate is both produced in the heater and collected from
the venting system. Therefore, the installation requires a condensate drain from
the secondary heat exchanger (FIGURE 21) and a condensate drain from the vent
pipe (FIGURE 22).
CAUTION: Apply general plumbing practices if pipe
insulation or heat tapes are required to prevent freezing
of the condensate drain system.
For safe performance of the heater, each condensate drain must include a trap as
shown in FIGURES 21 and 22.
Downstream from the traps the condensate drains may be joined and both must
be connected to a sanitary drain within the building. Check codes to be certain that
this is permitted. (Condensate from the heater has a ph of 6 and is not harmful to
a sanitary drain. NOTE: Actual ph may vary ± 1 depending upon fuel and combus-
tion air.) Model UEAS Sizes 130 and 180 will produce approximately one gallon (4
liters) of condensate per hour. Sizes 260 and 310 will produce approximately two
gallons (8 liters) of condensate per hour.
A condensate disposal system that relies on gravity should be satisfactory for most
installations since unit heaters are normally installed several feet above the oor.
If a gravity system is not possible, a condensate pump may be installed. There
are a number of commercially available pumps made for this purpose. If using a
condensate pump, follow the pump manufacturer’s installation recommendations.
Condensate Drain Traps
Two condensate drain traps are required.
• FIGURE 21 illustrates the trap in the drain attached
to the heater and lists the minimum required leg
dimensions for that trap.
• FIGURE 22 illustrates the vent pipe drain trap and lists
the required length difference for the trap legs.
The most important part of fabricating and assembling the traps is the length of
the individual legs of the traps. If the difference in the lengths of the legs of the
traps are not as illustrated, it could prevent proper drainage of the condensate and
possibly permit vent gas to enter the building. (The length difference is also what
provides a “water seal” that prevents leakage of vent gas into the sanitary drain.)
The two traps may be drained into a common pipe that is connected to the sanitary
drain.
The orientation of the piping is not critical and may be arranged to suit the installa-
tion. Unions are recommended to permit maintenance of the drains and to facilitate
service of the heater. A union is shown in both of the traps and a third union is rec-
ommended in the drain pipe. If pipe insulation or heat tapes are required to prevent
freezing, use should be in accordance with general accepted plumbing practices.
7.0 Mechanical
(cont’d)
Form I-UEAS, Page 26