34 Installing the Water Heater
3.5 Venting the Water Heater
(Indoor Models Only)
DANGER
This appliance is certified as a Category III
appliance and requires a special venting system.
The vent system operates with a positive
pressure in the pipe.
To prevent serious injury or death:
●
ALWAYS vent exhaust gases directly outdoors
using the vent materials and following these
instructions.
●
DO NOT connect vent connectors serving
appliances vented by natural draft into
any portion of mechanical draft systems
operating under positive pressure.
WARNING
Improper venting of the water heater can result
in excessive levels of carbon monoxide and can
lead to serious injury or death.
This water heater must be vented in accordance
with the “Venting of Equipment” section of
the latest edition of the ANSI Z223.1/NFPA
54 Natural Fuel Gas Code in the USA and/or
the “Venting systems and air supply for water
heaters” section of the latest version of the CAN/
CGA B149.1 Natural Gas and Propane Installation
Code in Canada, as well as all applicable local
building codes and regulations.
To prevent serious injury or death:
●
ONLY licensed professionals should install
venting.
●
ALWAYS follow all regulations, codes, and
instructions when venting the water heater.
●
ALWAYS seal the venting system gastight
to prevent flue gas leakage and carbon
monoxide emissions.
●
The building owner is responsible to maintain
the exhaust and intake terminations free of
snow, ice, or other potential blockages, as
well as scheduling routine maintenance.
The water heater is a Category III appliance
designed for use with a concentric venting system,
which uses one pipe with two ducts for combustion
air and exhaust air, respectively.
The water heater must be properly vented to
ensure a constant supply of clean intake air and to
ensure that exhaust air is properly removed from
living areas. The vent system must vent directly to
the outside of the building and use outside air for
combustion. When venting the water heater, it shall
be installed in accordance with the water heater
manufacturer’s instructions. Review the following
guidelines:
●
Do not install the water heater in areas with
contaminated air (containing a high level of dust,
sawdust, sand, flour, aerosols, or any other such
airborne contaminants), as contaminants can
cause operational problems. The warranty does
not cover damage caused by contaminants in the
installation area.
●
Do not use PVC, CPVC, ABS, or any galvanized
material to vent the water heater.
●
Do not combine any vent components or parts
from different manufacturers.
●
Do not reduce the vent diameter.
●
Do not connect the venting system with an
existing vent or chimney.
●
Do not vent in common with the vent pipe of any
other water heater or appliance.
●
For best results, keep the venting system as short
and straight as possible.
●
Locate the water heater as close as possible to the
vent termination.
●
For horizontal runs, slope the horizontal section
upward toward the vent termination at a
rate of
1
/
4
in per foot (2 % slope) when using
a condensate collector. Slope the horizontal
section downward toward the vent termination
when not using a condensate collector. Refer
to the manufacturer’s instructions for using a
condensate collector.
●
Create an airtight seal at the joint in the vent pipe
that leads from the water heater collar to the
vent termination by fully inserting the vent pipe
into the water heater collar. The vent pipe must
be inserted 1.3 in (34 mm) into the water heater
collar. Once fully inserted, mark the vent pipe with
a permanent marker directly above the water
heater collar to observe any displacement during
the installation process. If displaced, then readjust
the vent pipe to ensure full insertion into the
water heater collar.
Summary of Contents for NHW700
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