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.

FIGURE21.

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 Deflection 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 fittings, 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 fittings.

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 first hanger (or support) be located on the horizontal run immediately adjacent to the first 90-degree elbow from the vertical rise. Support method used should isolate the vent pipe from the floor 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 fittings 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 NOTALLOWED. 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° VentTerminal 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 flue 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 five 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.