Service manual

VVeennttiinngg
GGeenneerraall VVeennttiinngg AAiirr IInnssttrruuccttiioonnss
1. Installation of venting must conform with local building codes,
or in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1 (NFPA 54) - Latest Edition. In Canada,
installation must be in accordance with CAN/CGA-B149.1 for
natural gas units and CAN/CGA-B149.2 for propane units.
2. All vertically vented units with single-stage controls are
Category I. All vertically vented units with two-stage or
modulating controls are Category II. The installation of a
Category II unit must conform to the requirements from Table
4.1 in addition to those listed below.
3. From Tables 2.1, 2.2 or 3.1, select the size of vent pipe that
fits the flue outlet. Do not use a vent pipe smaller than the size
listed. The pipe should be galvanized steel or other suitable
corrosion resistant material. Follow the National Fuel Gas
Code for minimum thickness of vent material. The minimum
thickness for connectors varies depending on the pipe
diameter.
4. Vent pipes should be fitted with a tee with a drip leg and a
clean out cap to prevent against the possibility of any moisture
in the vent pipe from entering the unit. The drip leg should be
inspected and cleaned out periodically during the heating
season.
5. The National Fuel Gas Code requires at least 6 inches from
combustible materials for single wall vent pipe. The minimum
distance from combustible materials is based on the
combustible material surface not exceeding 160°F. Clearance
from the vent pipe (or the top of the unit) may be required to
be greater than 6 inches if heat damage other than fire (such
as material distortion or discoloration) could result.
6. Avoid venting through unheated space. When venting does
pass through an unheated space, insulate runs greater than
5 feet to minimize condensation. Inspect for leakage prior to
insulating and use insulation that is noncombustible with a
rating of not less than 350°F. Install a tee fitting at the low
point of the vent system and provide a drip leg with a clean out
cap as shown in Figure 5.1.
7. When the vent passes through an interior wall or floor, a metal
thimble 4 inches greater than the vent diameter is necessary.
If there is 6 feet or more of vent pipe in the open space
between the appliance and where the vent pipe passes
through the wall or floor, the thimble need only be 2 inches
greater than the diameter of the vent pipe. If a thimble is not
used, all combustible material must be cut away to provide 6
inches of clearance. Any material used to close the opening
must be noncombustible.
8. Do NOT use dampers or other devices in the vent or
combustion air pipes.
9. Precautions must be taken to prevent degradation of
building materials by flue products.
10. The outlet of the vent should extend as shown in Figure 5.1
and Table 4.2 for vents 12” in diameter or smaller that do not
terminate within 10’ of a vertical wall or similar obstruction. For
vents larger than 12” or vents that terminate within 10’ of a
vertical wall or similar obstruction the terminal outlet must be a
minimum of 2’ higher than the vertical wall or similar
obstruction within a distance of 10’ (refer to Figure 5.2)
11. Use a vent terminal to reduce downdrafts and moisture in
vent. A vent terminal that is very open will avoid spillage at
unit’s diverter relief opening and tripping of the blocked vent
safety switch.
CAUTION
Installation must conform with local building codes or in the
absence of local codes, with Part 7, Venting of Equipment, of
the National Fuel Gas Code, ANSI Z223.1 (NFPA 54) - Latest
Edition. In Canada, installation must be in accordance with
CAN/CGA-B149.1 for natural gas units and CAN/CGA-B149.2
for propane units.
DDiimmeennssiioonnaall DDaattaa ––
MMooddeell PPVV--112244 wwiitthh 2244--VVoolltt RReellaayy CCoonnttrrooll
WARNING
1. Gas fired heating equipment must be vented - do not
operate unvented.
2. A built-in draft diverter is provided - additional external
power exhausters are not required or permitted.
3. Gas-fired heating equipment which has been improperly
vented, or which experiences a blocked vent condition may
have flue gasses accidentally spilled into the heated space.
See unit installation and service manual for specific
information about the blocked vent safety switch supplied
on the unit.
4. If you are replacing an existing, heater, it may be necessary
to resize the venting systems. Improperly sized venting
systems can result in vent gas leakage of the formulation
of condensate. Refer to the National Fuel Gas Code ANSI
Z223.2 or CAN/CGA B149.1 or .2 latest edition. Failure to
follow these instructions can result in serious injury or death.
AApppplliiaannccee VVeennttiinngg
CCaatteeggoorryy DDeessccrriippttiioonn RReeqquuiirreemmeennttss
II
Negative vent pressure Follow standard venting
Non-condensing requirements.
IIII
Negative vent pressure Condensate must be
Condensing drained.
IIIIII
Positive vent pressure Vent must be gastight.
Non-condensing
IIVV
Positive vent pressure Vent must be liquid and
Condensing gastight. Condensate must
be drained.
TTaabbllee 44..11
AANNSSII VVeennttiinngg RReeqquuiirreemmeennttss
Rise Roof Pitch Min Height
X (in) H (ft)*
0-6 Flat to 6/12 1.00
6-7 6/12 to 7/12 1.25
7-8 7/12 to 8/12 1.50
8-9 8/12 to 9/12 2.00
9-10 9/12 to 10/12 2.50
10-11 10/12 to 11/12 3.25
11-12 11/12 to 12/12 4.00
12-14 12/12 to 14/12 5.00
14-16 14/12 to 16/12 6.00
16-18 16/12 to 18/12 7.00
18-20 18/12 to 20/12 7.50
20-21 20/12 to 21/12 8.00
TTaabbllee 44..22
MMiinniimmuumm HHeeiigghhtt ffrroomm RRooooff ttoo
LLoowweesstt DDiisscchhaarrggee OOppeenniinngg
* Size according to expected snow depth.
IINNSSTTAALLLLAATTIIOONN
44