Rinnai REU-VA1320WF-US Operation And Installation Manual page 17

Venting Requirements
Vent Dampers
Vent dampers must be certified in accordance with ANSI Z21.68
Before installing any flue damper, consult the local gas authority and damper manufacturer for proper
installation.
WARNING
Thermal Operated Vent Dampers: Should NOT be used with this appliance. This appliance has a thermal efficien-
cy greater than 80%. This higher efficiency will result in lower flue gas temperatures. Such temperatures may be
too low to activate a thermal operated vent damper. Use of a thermal operated flue damper on this product may
result in spillage of exhaust gases and ultimately carbon monoxide poisoning.
Vent Inspection
The entire vent system (Combustion air ducts, louvers etc., and exhaust vent) must be checked periodically for
signs of obstruction or damage. If damaged components are observed they must be repaired or replaced
immediately.
Vent Size
This water heater is equipped with a 4" vent adapter and must never be attached to a vent smaller than 4".
Certain applications may require vent diameters greater than 4" Consult your local gas supplier or authority to
aid in the proper vent diameter selection per the requirements of the vent tables in the current edition of the
National Fuel Gas Code ANSI Z223.1/NFPA 54.
Vent Connectors
Vent Connectors are relatively short runs of vent connecting the appliance to the chimney or vertical vent run.
Following is a list of appropriate vent connector material for use between the water heater and the chimney:

Type B (B-Vent) Double wall, U.L. listed vent pipe

Type B (B-Vent) Single wall, U.L. listed vent pipe
Note the following when installing a vent connector from the appliance to the chimney or vertical vent:
Length: A vent connector shall be as short as practical and the appliance located as close as practical to the
chimney or vent. The maximum horizontal length of the vent connector cannot exceed 75% of the
height of the chimney or vent. Unnecessary bends should be avoided as to not create excessive
resistance to flow of vent gases.
Prohibited locations: Vent Connectors cannot pass through any ceiling, floor, firewall, or fire partition.
Single wall vent connectors: A single wall vent
connector must not pass through any interior
walls, floors or ceilings. A single wall vent
connector must not be installed in attics, crawl
spaces or any other confined space or inaccessible
location. Maintain a minimum of 6" from
combustibles when using single walled vent
connectors.
Double Walled, B-Vent: It is acceptable to pass
through walls or partitions with double walled, B-
Vent.
Slope: Vent connectors must pitch ¼ inch per foot
(21mm per meter) upward.
RH180 Manual
CHIMNEY
OR
LISTED VENT
Vent Connector
MIN. ¼ inch rise
per foot
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