Installation Guide
13 Page
Installaon
Installaon Manual
VENTING INSTRUCTIONS
Indoor models
-General-
WARNING
 Improper venting of this appliance can result in excessive levels of carbon 
monoxide which can result in severe personal injury or death.
 Improper installation can cause nausea or asphyxiation, severe injury or death 
from carbon monoxide and flue gases poisoning. Improper installation will void 
product warranty.
 When installing the vent system, all applicable national and local codes must be 
followed. If you install thimbles, fire stops or other protective devices and they 
penetrate any combustible or noncombustible construction, be sure to follow 
all applicable national and local codes.
The Indoor model must be vented in accordance with “Venting of Equipment" in the current edition of the 
National Fuel Gas Code: ANSI Z223.1/NFPA 54 in the United States and/or Section 8 of the B149.1 Natural 
Gas and Propane Installation Code in Canada, as well as applicable local building codes.
The use of venting materials approved for Category III/IV appliances is recommended whenever possible. 
However, the Indoor model may also be vented with plastic 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) Section on p. 18. Vent installations in Canada which utilize plastic vent systems must 
use venting that complies with ULC S636.
General rules for venting water heaters:
 Place the water heater as close as possible to the vent termination.
 The vent collar of the water heater must be fastened directly to an unobstructed vent pipe.
 Do not weld 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 inspection of 
the unit.
 The water heater vent must not be connected to any other gas appliance or vent stack except an approved 
common-venting system. Refer to pp. 24 and 25.
 Avoid using an oversized vent pipe or using extremely long runs of the pipe unless it is part of an approved 
common vent system.
 Air supply pipe can be made of ABS, PVC (solid core), CPVC (solid core), polypropylene, corrugated stainless 
steel, or Category lll / IV stainless steel. Regarding exhaust pipe, refer to pp.18 to 23.
 Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel® (polyphenylsulfone) in nonmetallic 
venting systems is prohibited. Covering non-metallic vent pipe and fittings with thermal insulation is 
prohibited.
 Sidewall venting is recommended for the Indoor model. Vertical venting (roof termination) is acceptable.
 The manufacturer recommends running the exhaust vent and the intake pipe as parallel as possible.
 For rooftop venting, a rain cap or other form of termination that prevents rain water from entering into 
the water heater must be installed.
 Do not terminate vent into a chimney. 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 flue serving a separate appliance, designed to burn 
solid fuel.
General rules for vent terminations:
 Avoid locating the water heater vent termination near any air intake devices. These fans can pick up the 
exhaust flue products from the water heater and return them to the building. This can create a health 
hazard.
 Locate the vent termination so that it cannot be blocked by any debris, at any time. Most codes require 
that the termination be at least 12 in (305 mm) above grade and anticipated snow level, but the installer 
may determine if it should be higher depending on the job site condition and applicable codes.
 A proper sidewall termination is recommended when the water heater is vented through a sidewall.
 Regarding the clearances from the exhaust termination to the air inlet or opening, refer to pp. 26 to 28.










