18
VENT CONNECTIONS TO BLOWER ASSEMBLY
Figure 21 shows the optimal placement of the 2” to 3” or 3” to 4” reducer;
however, the vent can be reduced at any point in the vent system as long
as the maximum vent length is not exceeded.
FIGURE 21.
VENTING AND INSTALLATION
Plan the layout of the vent system from the vent termination to the water
heater considering all of the 90° and 45° elbows plus the number of feet
of pipe that would be needed to install the total vent system. The water
heater must be vented to the outdoors as described in these instructions.
DO NOT connect this water heater to an existing vent or chimney. It must
be vented separately from all other appliances. Nonmetallic vent may be
used if it has “Heat Defl ection Temperature” (HDT@66 psi) or 455 kPa of
at least 157°F or 69°C. Typical nonmetallic vent materials meeting this
requirement are: PVC (Schedule 40, ASTM D-1785), Coex Cellular Core
(Schedule 40, ASTM F-441), CPVC (Schedule 40, ASTM D-2846), ABS
(Schedule 40, ASTM D-2661). The fi ttings, other than the supplied Vent
Termination should be equivalent to the following: PVC (Schedule 40,
DWV, ASTM D-2665), CPVC (Schedule 40, DWV, ASTM F-438), ABS
(Schedule 40 DWV, ASTM D-2661).
The cement used should be as recommended by the vent pipe
manufacturer. See the instructions on pages 20 and 21 for the proper
method of cutting and cementing the PVC pipe and fi ttings.
The unit may be vented horizontally through a wall or vertically through
the roof. Pipe runs must be adequately supported along both vertical
and horizontal runs as follows:
• For Schedule 40, 2” PVC, ABS, Coex Cellular Core vent pipe: Every
3 feet (0.9 m).
• For Schedule 40, 3” PVC, ABS, Coex Cellular Core vent pipe: Every
3.5 feet (1.1 m).
• For Schedule 40, 4” PVC, ABS, Coex Cellular Core vent pipe: Every
4 feet (1.2 m).
• For Schedule 40, 2” CPVC vent pipe: Every 5 feet (1.5 m).
• For Schedule 40, 3” CPVC vent pipe: Every 6 feet (1.8 m).
• For Schedule 40, 4” CPVC vent pipe: Every 6.5 feet (2.0 m).
It is imperative that the fi rst hanger (or support) be located on the
horizontal run immediately adjacent to the fi rst 90-degree elbow from
the vertical rise. Support method used should isolate the vent pipe from
the fl oor joists or other structural members to prevent the transmission
of noise and vibration. Do not support, pin, or otherwise secure the
venting system in a way that restricts the normal thermal expansion and
contraction of the chosen venting material.
If the water heater is being installed as a replacement for an existing
power vented heater in pre-existing venting, a thorough inspection of
the existing venting system must be performed prior to any installation
work. Verify that the correct material as detailed above has been used,
and that the minimum or maximum vent lengths and terminal location
as detailed in this manual have been met. Carefully inspect the entire
venting system for any signs of cracks or fractures, particularly at the
joints between elbows and other fi ttings and the straight runs of vent pipe.
Check the system for signs of sagging or other stresses in the joints as
a result of misalignment of any components in the system. If any of
these conditions are found, they must be corrected in accordance with
the venting instructions in this manual before completing the installation
and putting the water heater into service.
Except where instructed in this manual, the mixing of 2”, 3” and 4” vent
pipe is NOT ALLOWED. If 2” pipe is to be used, then a 2” to 3” bell
reducer is recommended. Figure 21 shows the recommended location
for the bell reducer. If the bell reducer is located at the rubber boot on the
blower assembly, then a short section of 3” vent pipe needs to be installed
in the rubber boot for proper connection of the 2” to 3” bell reducer. That
length can be the minimum length required for the connection.
If 4” pipe is to be used, then a 3” to 4” bell reducer is recommended.
Figure 21 shows the recommended location for the bell reducer. If the
bell reducer is located at the rubber boot on the blower assembly, then
a short section of 3” vent pipe needs to be installed in the rubber boot
for proper connection of the 3” to 4” bell reducer. That length can be
the minimum length required for the connection.
The water heaters covered by this manual are supplied with a 2”
Schedule 40 PVC 22.5° Vent Terminal. If you decide to vent with 3”
or 4” pipe, a Schedule 40 DWV 45° Vent Terminal must be used. For
your convenience, we have included a screen for both 3” and 4” Vent
Terminals.
The vent piping should be connected to the blower with a rubber adapter
and secured with hose clamps. The adapter and clamps are provided
with the heater.
Even though the fl ue gas temperature leaving the blower is between
140°F (69°C) and 175°F (79°C), some installations will have water
vapor condense in the vent piping. If this occurs, then adequate means
of draining and disposing of the condensate needs to be made by
the installer.
CONDENSATION
Condensate formation does not occur in all installations of power vented
water heaters, but should be protected against on installations where it
can form in the venting system. Condensation in the venting system of
power vented water heaters is dependent upon installation conditions
including, but not limited to ambient temperature and humidity of
installation location, ambient temperature and humidity of venting space,
vent discharge and slope, and product usage. In certain conditions,
installations in unconditioned space or having long horizontal or vertical
vent runs may accumulate condensate. In these conditions, the vent
pipe should be sloped downward away from the blower assembly 1/4”
(6.4 mm) per fi ve feet (1.5 m) of pipe but not more than 1 1/2” (3.8 cm) in
the total vent length. If the vent piping is vented level or sloped upwards
away from the blower assembly, then adequate means for draining
and disposing of the condensate needs to be made by the installer
(if condensate is detected). If you have condensate, then a 3/8” drain
hose can be connected to the built-in drain port of the rubber boot on
the blower assembly. For your convenience, the rubber boot is supplied
with a removable cap on the built-in drain port. Prior to operating the
water heater, make sure the removable cap is installed on the drain port
(if a drain hose is not needed).
MAXIMUM VENT LENGTHS
40,000 BTU Units:
For 2” Venting, the maximum equivalent feet of pipe allowed is 40
feet (12.2 m).
This does not include the supplied vent termination for the
water heater. For the 2” venting, one 90° elbow is approximately equal
to 5 feet (1.5 m). One 45° elbow is approximately equal to 2.5 feet (0.8
m). It is recommended that at least 2 feet (0.6 m) of spacing be used in
between all 45° elbows and all 90°elbows.
For 3” Venting, the maximum equivalent feet of pipe allowed is
120 feet (36.6 m).
This does not include the Vent Termination (supplied
locally) for the water heater. For the 3” venting, one 90° elbow is
approximately equal to 5 feet (1.5 m). One 45° elbow is approximately
equal to 2.5 feet (0.8 m). It is recommended that at least 2 feet (0.6 m)
of spacing be used in between all 45° elbows and all 90°elbows.
For 4” Venting, the maximum equivalent feet of pipe allowed is
160 feet (48.8 m).
This does not include the Vent Termination
(supplied
locally) for the water heater. For the 4” venting, one 90° elbow is
approximately equal to 8 feet (2.4 m). One 45° elbow is approximately
equal to 4 feet (1.2 m). It is recommended that at least 2 feet (0.6 m) of
spacing be used in between all 45° elbows and all 90°elbows.
