2
General venting
Minimum
/
combustion air and vent piping lengths are
as follows:
Vent = 12 equivalent feet minimum / 100 equivalent feet
maximum
Combustion Air (when used) = 12 equivalent feet minimum /
100 equivalent feet maximum
When determining equivalent combustion air and vent length,
add 5 feet for each 90° elbow and 3 feet for each 45° elbow.
EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2) 45°
elbows + (1) concentric vent kit (CVK3003) = 49 equivalent feet
of piping.
Table 2C Equivalent Vent Lengths
Model
SNR150-100 -- SNR200-100
SNA285-125
SNA400-125
SNA500-125
Removing from existing vent
Follow the instructions in Section 1, page 11 of this manual
when removing a water heater from an existing vent system.
Vent and air piping
Vent and air system:
Installation must comply with local
NOTICE
requirements and with the National Fuel Gas
Code, ANSI Z223.1 for U.S. installations or
CSA B149.1 for Canadian installations.
You may use any of the vent/air piping methods covered in this
manual. Do not attempt to install the Shield water heater using
any other means.
DO NOT mix components from different
WARNING
systems. The vent system could fail, causing
leakage of flue products into the living space.
Use only PVC or CPVC and fittings, with
primer and cement specifically designed for
the material used.
(continued)
Maximum
allowable
Kit
Equivalent
Number
Vent Length
CVK3003
3 feet
CVK3007
3 feet
CVK3007
5 feet
CVK3007
30 feet
TM
Vent, air piping and termination:
The Shield water heater vent and air piping can be installed
through the roof or through a sidewall. Follow the procedures
in this manual for the method chosen. Refer to the information
in this manual to determine acceptable vent and air piping
length.
Air contamination
Pool and laundry products and common household and hobby
products often contain fluorine or chlorine compounds. When
these chemicals pass through the water heater, they can form
strong acids. The acid can eat through the water heater wall,
causing serious damage and presenting a possible threat of flue
gas spillage or appliance water leakage into the building.
Please read the information given in Table 1A, page 10, listing
contaminants and areas likely to contain them. If contaminating
chemicals will be present near the location of the water heater
combustion air inlet, have your installer pipe the water heater
combustion air and vent to another location, per this manual.
If the water heater combustion air inlet is
WARNING
located in a laundry room or pool facility, for
example, these areas will always contain
hazardous contaminants.
To prevent the potential of severe personal
WARNING
injury or death, check for areas and products
listed in Table 1A, page 10 before installing
the water heater or air inlet piping.
If contaminants are found, you MUST:
• Remove contaminants permanently.
• Relocate air inlet and vent terminations
to other areas.
Installation & Service Manual
—OR—
17