Venting
Never operate the water heater unless it is vented to the outdoors.
The instructions in this section of the manual must be followed to avoid choked combustion or recirculation of flue gases. Such conditions cause sooting of the combustion chamber, burners and flue tubes and creates a risk of asphyxiation.
For direct vent application where combustion air might be supplied from extremely cold ambient through fresh air intake piping system, it is recommended that a backflow preventer be installed at the intake vent terminal close to the blower before proceeding with installation of the rest of the fresh air intake piping. Call the technical support phone number listed on the back cover of this manual for more information.
VENT PIPE TERMINATION
The first step is to determine where the vent pipe will terminate. See Figures 15, 16, 17 and 18. The vent may terminate through a sidewall as shown in Figures 15 and 16 or through the roof as shown in Figures 17 and 18.
The vent system must terminate so that proper clearances are maintained as cited in local codes or the current edition of the National Fuel Gas Code, (ANSI Z223.1, 12.9.1 through 12.9.4). See Figures 13 and 14.
Instructions on proper installation through a sidewall are provided in Figures 15A, 15B, 15C, and 16.
Plan the vent system layout so that proper clearances are maintained from plumbing and wiring.
Vent pipes serving power vented appliances are classified by building codes as “vent connectors”. Required clearances from combustible materials must be provided in accordance with information in this manual under Facts to Consider About Location and INSTALLING THE WATER HEATER, and with the National Fuel Gas Code and local codes.
PLANNING THE VENT SYSTEM
Plan the route of the vent system from the exhaust elbow to the planned location of the vent terminal.
1.Layout total vent system to use a minimum of vent pipe and elbows.
2.This water heater is capable of venting flue gases equivalent to 45’ (13.7 m) of 2” pipe, 128’ (39 m) of 3” pipe as listed in Table 5.
Table 5
Number of | 2” Maximum | 3” Maximum |
90° Elbows | Pipe - ft. (m) | Pipe - ft. (m) |
1 | 40 (12.19) | 120 (36.57) |
2 | 35 (10.66) | 115 (35.05) |
3 | 30 (9.14) | 110 (33.52) |
4 | 25 (7.62) | 105 (32) |
5 | 20 (6.09) | 100 (30.48) |
6 | 15 (4.57) | 95 (28.95) |
The minimum vent length for each pipe size is one 90° plus 2’ (61 cm) of straight pipe and the appropriate termination.
NOTE: The equivalent feet (m) of pipe listed above are exclusive of the termination. That is, the termination, with an installed screen, is assumed to be in the system and the remainder of the system must not exceed the lengths discussed above.
3.The exhaust elbow assembly is designed to accept only straight sections of 2” pipe. To start, a minimum 2” (5.1cm) maximum 6” long of 2” pipe must be inserted and glued to the exhaust elbow assembly if utilizing 3” vent pipe. Use the same method with the blower inlet if a direct vent configuration is utilized.
If using 2” inch vent pipe:
A minimum of 2” (5.1cm) diameter vent pipe must be attached to the exhaust elbow assembly. The total system cannot exceed the lengths discussed above, where each elbow is equal to 5 equivalent feet (1.5m) of straight pipe.
If using 3” inch vent pipe:
Two inches (5.1cm) of 2” pipe must be attached to the exhaust elbow assembly before adding a reducer to acquire the desired pipe diameter. An appropriately sized 45 degree elbow (supplied
NOTE: This unit can be vented with PVC pipe materials (DWV
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