Residen al Gas Tankless Water Heater Use and Care Guide • 21
INSTALLATION
Ven ng
WARNING! Carbon Monoxide
Hazard. This water heater must
be supplied with adequate air and
vented to outdoors. The vent system
must be installed by a quali
fi
ed
person. Examples of a quali
fi
ed
person include gas technicians,
authorized gas company personnel,
and authorized service technicians.
Failure to properly vent the water
heater can result in severe injury
or death from carbon monoxide
poisoning.
The Indoor model must be vented in
accordance with the current edi on
of ANSI Z223.1/NFPA 54, Na onal
Fuel Gas Code in the USA or B149.1,
Natural gas and propane installa on
code in Canada, as well as applicable
local building codes.
The use of ven ng materials approved
for Category III/IV appliances is
recommended whenever possible.
However, the Indoor model may also
be vented with plas c pipe materials
such as ABS, PVC (solid core), CPVC
(solid core), or polypropylene.
For details, please refer to the
Exhaust Vent (ABS, PVC, CPVC, or
Polypropylene Vent) Sec on on page
23. Vent installa ons in Canada
which u lize plas c vent systems must
use ven ng that is cer
fi
ed to ULC
S636.
Ven ng may not intermingle with
other manufactured material types,
other than approved adapters.
General rules for ven ng water
heaters:
• Follow the vent pipe manufacturer’s
instruc ons when installing the vent
pipe.
• Place the water heater as close as
possible to the vent termina on.
• The vent collar of the water heat-
er must be fastened directly to an
unobstructed vent pipe.
• Do not weld, glue, or permanently
bond the vent pipe to the water
heater’s vent collar.
• Do not cut or alter the vent collar of
the unit.
• The vent must be easily removable
from the top of the water heater for
normal service and inspec on of the
unit.
• The water heater vent must not be
common vented to any other gas
appliance or vent stack.
• Air supply pipe can be made of ABS,
PVC (solid core), CPVC (solid core),
polypropylene, or Category lll/IV
stainless steel.
• Use of cellular core PVC (ASTM
F891), cellular core CPVC, or Radel®
(polyphenylsulfone) in nonmetallic
ven ng systems is prohibited
• Covering non-metallic vent pipe and
fi
ngs with thermal insula on is
prohibited.
• Sidewall ven ng is recommended
for the Indoor model. Ver cal vent-
ing (roof termina on) is acceptable.
• The manufacturer recommends run-
ning the exhaust vent and the intake
pipe as parallel as possible.
• For roo op ven ng, a rain cap or
other form of termina on that pre-
vents rain water from entering into
the water heater must be installed.
• Do not terminate vent into a chim-
ney. If the vent must go through
the chimney, the vent must run all
the way through the chimney with
approved vent pipe.
• The water heater shall not be
connected to a chimney
fl
ue serving
a separate appliance, designed to
burn solid fuel.
General rules for vent termina ons:
• Avoid loca ng the water heater
vent termina on near any air intake
devices. These fans can pick up
the exhaust
fl
ue products from the
water heater and return them to the
building. This can create a health
hazard.
• Locate the vent termina on so that
it cannot be blocked by any debris,
at any me. Most codes require
that the termina on be at least 12 in
(305 mm) above grade and an ci-
pated snow level, but the installer
may determine if it should be higher
depending on the job site condi on
and applicable codes.
• A proper sidewall termina on is rec-
ommended when the water heater
is vented through a sidewall.
• Check the clearances from the
exhaust termina on to the air inlet
or opening.
• To reduce the risk of carbon
monoxide poisoning, install a fuel
gas and carbon monoxide detector.
Install and maintain the detector in
accordance with the manufacturer’s
instruc ons and local codes.
Replacing a Water Heater
Using the Exis ng Vent System
WARNING! Improper ven ng of
this appliance can result in excessive
levels of carbon monoxide which
can result in severe personal injury
or death. Improper installa on
can cause nausea or asphyxia on,
severe injury or death from carbon
monoxide and
fl
ue gases poisoning.
Improper installa on will void
product warranty.
Do not use Category I or Category
II ven ng systems with this water
heater.
If exis ng ven ng and vent
termina ons are used, they MUST be
cleared of ALL restric ons for proper
opera on, such as a restricter plate.
Read the “Installing Vent Pipe” sec on
of this manual and make sure your
vent system is properly installed.
Inspect the exis ng vent system for
obstruc ons, corrosion, and proper
installa on. Repair or replace if
necessary.
