Troubleshooting guide

12
Direct Vent Terminal Clearances
Canadian Installations
1
US Installations
2
A= Clearance above grade, veranda, porch, deck or balcony 12 inches (30 cm)
12 inches
(30 cm)
B= Clearance to widow or door that may be opened 36 inches (91 cm) 12 inches (30 cm)
C= Clearance to permanently closed widow *b *b
D=
Vertical clearance to ventilated soffit located above the terminal within a
horizontal distance of 2 feet (61 cm) from the center line of the terminal
12 inches (30 cm) *a 12 inches (30 cm) *a
E= Clearance to unventilated soffit 12 inches (30 cm) *a 12 inches (30 cm) *a
F= Clearance to outside corner *b *b
G= Clearance to inside corner *b *b
H=
Clearance to each side of center line extended above meter/regulator
assembly
3 feet (91 cm) within a height 15
feet (4.6 m) above the
meter/regulator assembly
*b
I= Clearance to service regulator vent outlet or oil tank vent 36 inches (91 cm) *b
J=
Clearance to non-mechanical air supply inlet to building or the combustion air
inlet to any other appliance
36 inches (91 cm) 12 inches (30 cm)
K= Clearance to a mechanical air supply inlet 6 feet (1.83 m)
3 feet (91 cm) above if within 10
feet horizontally
L= Clearance above paved sidewalk or paved driveway located on public property 7 feet (2.13 m)† *b
M= Clearance under a veranda, porch, deck, or balcony 12 inches (30 cm) ‡ *b
1
In accordance with the current CAN/CGA-B149 Installation Codes.
2
In accordance with the current ANSI Z223.1-(Latest edition)/NFPA 54 National Fuel Gas Code.
† A vent must not terminate directly above a sidewalk or paved driveway that is located between two single-family dwellings and serves both dwellings.
‡ Permitted only if a veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor.
*a) A minimum clearance value determined by testing in accordance with section 2.20.
*b) “Clearance in accordance with local installation codes and the requirements of the gas supplier”.
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 must terminate a minimum of 12 inches above expected snowfall level to prevent blockage of vent termination.
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.