KBD Series Manual
21
All PVC/CPVC IPEX Concentric Vent Kit (CVK)
Assemblies are certified to ULC S636. Where ULC S636
compliance is required, use only System 636 pipe,
fittings, and cement at terminal connection.
DO NOT
use PVC/CPVC on Non-Condensing Units.
DO NOT
operate unit until venting is completely
installed and all solvents and glues have bonded.
All PVC/CPVC exhaust vent material used in
Canada must be S636 certified.
For further details on listed PVC/CPVC venting
material (table below) refer to the installation manual of
the PVC/CPVC manufacturer.
Twin Pipe PVC/CPVC Vent Installation Requirments:
Vent and Air Piping Materials
Item
Material
Standard for Installation in North America
United States
Canada
Thermoplastic Piping Materials
Vent or combustion air
intake pipe & Fittings
PVC schedule 40
ANSI/ASTM D1785
Thermoplastic vent pipe must be
certified to ULC S636.
Intake pipe may be of any material listed
(left).
PVC-DWV
ANSI/ASTM D2665
CPVC schedule 40
ANSI/ASTM F441
PVC pipe cement &
primer
PVC
ANSI/ASTM D2564
CPVC
ANSI/ASTM F493
IPEX bird screens (purchase separately)
Termination Vent
Screens
Polyethylene
3" Vent screen: IPEX part # 196051; 4" Vent screen: part #: 196052
(Screens are friction fitted inside termination fitting bells.)
The listed vent, vent fittings, termination, cleaner, and glue are all certified as part of the condensing tankless
water heater vent system.
NOTE
DANGER
Failure to correctly install vent and combustion air intake pipes of the water heater to atmosphere as outlined
in this venting section will result in death from asphyxiation (from carbon monoxide), fire, or explosion.
NEVER
operate the water heater without proper venting (vent and combustion air intake). Always inspect the vent
terminal unit, combustion air intake pipe, and the entire vent system affixed to the water heater for proper
installation at equipment commissioning and at least annually thereafter.
IMPORTANT CONSIDERATIONS FOR LOCATION:
Locate the vent outlet where flue gases will not harm
surrounding plants and/or cooling equipment.
Avoid locating vent where prevailing winds could
affect the performance of the water heater or cause
recirculation of the flue gases.
DO NOT
terminate the venting over a public walkway
or over an area where condensate or vapor can
create a nuisance / hazard or where condensate can
be detrimental to the operation of equipment such as
regulators or relief valves
Water Heater flue gases must be piped from the
appliance to the outside, Installer MUST adhere to the
instructions provided herein and the most
recent Water Heater Manual and all applicable codes.
Exhaust and combustion air must terminate through
the same sidewall or roof as the terminations must be
in the same pressure zone and face same direction.
Vent pipe must terminate either through the sidewall
or through the roof, exhaust/vent termination and/or
intake air openings shall adhere to clearances as set
forth in the Direct Vent Termination Clearances
diagram.
Each Condensing Tankless Water Heater requires a
separate vent system.
If common venting is required, refer to Rinnai
Common Vent Installation Manual (latest revision) for
instructions on specific allowable venting method as
well as to verify which tankless models may be
common vented.
For twin pipe installation use only 3” or 4” PVC/CPVC.
Terminations must be installed 12” above grade or
anticipated snow level.
