English
Installation
Maximum Vent Length
Owner must refer to vent manufacturer’s instructions and specifications.
The system will not operate if there is excessive restriction (pressure
drop) in the venting system. A maximum of 32 feet of vent pipe
may be used provided there is only one 90° elbow in the system. If
additional elbows are required: two elbows can be used with 27 feet,
and three elbows can be used with 22 feet of vent pipe.
A 90° elbow is equivalent to 5 feet of straight pipe. A 45° elbow is
equivalent to 2 feet 6 inches of straight pipe.
The termination elbow does not count as an elbow when
determining total vent lengths.
The vent must be installed with a slight downward slope of ¼” per
foot of horizontal run toward the vent terminal (see diagram below).
This ensures that any condensate formed during operation of the
unit evacuated from the water heater.
A ¼” per foot upward slope is acceptable when it is not possible to
vent with a downward slope, however, a UL approved Category III
Stainless Steel condensate trap MUST be installed at the beginning
of the horizontal run (See page 20 “Typical Horizontal Termination
w ¼” per foot UPWARD Slope” or page 14, “Standard Vertical Vent
Termination” for examples).
Number of
90° elbows
(bends)
Maximum
Length of
Straight Pipe
1
2
3
32’
27’
22’
One (1) 90° Elbow is
Equivalent to 5 Feet of
Straight Pipe
Minimum Vent Length
The venting may be as short as 12”,
provided one vent termination is
installed to the outdoors through a
sidewall, one 90° elbow is included in
the installation, and the wall thimble is
installed.
NOTICE:
Make sure that the seam
of the vent pipe in horizontal runs
is toward the top of the installation
(see illustration to the left)
Draining the Condensate
In certain conditions, installations in unconditioned space or having long horizontal or vertical
runs may accumulate condensate.
Condensate is known to be acidic; refer to local, state (provincial) or federal codes for proper
handling methods.
In order to prevent condensate from draining back into the water heater, we recommend a
condensate trap and drain to be installed in a horizontal vent section as close as practical to
the water heater vent connection.
Not following proper condensate procedures will void warranty.
Venting