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The vent system must terminate so that proper clearances are maintained as cited in local codes or the latest edition of the
National Fuel Gas Code
, ANSI Z223.1.73.4e and 7.8a, b as follows:
1. Do not terminate near soffit vents or crawl space or other area where condensate or vapor could create a nuisance or
hazard or cause property damage.
2. Do not terminate the exhaust vent terminal where condensate or vapor could cause damage or could be detrimental
to the operation of regulators, relief valves, or other equipment.
3. Do not terminate the exhaust vent terminal over public area or walkways where condensate or vapor can cause
nuisance or hazard.
4. The vent shall terminate a minimum of 12 inches (30.5 cm) above expected snowfall level to prevent blockage of
the vent termination.
5. The manufacturer requires the centerline distances between the air intake and exhaust vent terminals to be a
minimum of 36 inches (91.4 cm) apart and the exhaust terminal must extend 6 inches (15.2 cm) past the air intake
terminal.
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 LOCATION OF WATER
HEATER and CLEARANCES, and with National Fuel Gas Code
and local codes.
NOTICE
This unit can be vented using only PVC (Class 160, ASTM D-2241 Schedule 40, ASTM D-1785;
or Cellular Core Schedule 40 DWV, ASTM F-891), Schedule 40 CPVC (ASTM F-411), or ABS
(ASTM D-2661) pipe. The fittings, other than the TERMINATIONS
should be equivalent to PVC-
DWV fittings meeting ASTM F-2665. (Use CPVC fittings, ASTM F-438 for CPVC pipe and ABS
fittings, ASTM D-266/3311 for ABS pipe.) If CPVC or ABS pipe and fittings are used, then the
proper cement must be used for all joints, including joining the pipe to the Termination (PVC
material). PVC materials should use ASTM –D2564 grade cement; CPVC materials should use
ASTM F-493 grade cement; and ABS materials should use ASTM D-2235 grade cement.
For water heaters in locations with high ambient temperatures (above 100°F (38ºC)) and/or
insufficient dilution air, it is recommended that CPVC or ABS pipe and fittings (MUST USE
SUPPLIED VENT TERMINAL) be used.
Horizontal Installation:
In a horizontal application, it is important that condensate not be allowed to buildup in the exhaust vent pipe. To prevent this
from happening, the pipe should be installed with a slight upward slope so the condensate will run back toward the water
heater. The vent system must be supported every 5 feet (1.5 m) of vertical run and every 3 feet (.9 m) of horizontal run of vent
pipe length.
CAUTION
Failure to properly support the vent piping with hangers and clamps may result in damage to the water
heater or venting system.
Stress levels in the pipe and fittings can be significantly increased by improper installation. If rigid pipe clamps are used to
hold the pipe in place, or if the pipe cannot move freely through a wall penetration, the pipe may be directly stressed, or high
thermal stresses may be formed when the pipe heats up and expands. Install accordingly to minimize such stresses.
Follow the following procedure to vent through the wall:
1. Cut two 2 ½ inch (6.4 cm) diameter holes for 2 inch (5.1 cm) diameter pipe, in the wall with the centerline hole
distances at least 36 inches (91.4 cm) apart in the location where the exhaust vent and air intake terminals will exit the
outside wall if vented on the same wall. If venting with 3 inch (7.6 cm) pipe or 4 inch (10.2 cm) diameter pipe, use a
bell reducer to reduce to 2 inch (5.1 cm) pipe before exiting the wall to use the supplied 2 inch (5.1 cm) diameter vent
terminals.