Navien CR-180 Installation Manual page 25

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Venting:
� Do not store hazardous or flammable substances near the vent terminator;
� If this product will be installed in an area where snow is known to accumu late,
protect the vent termination from blockage;
� Vent terminator must be a minim u m of 1 2" above ground;
� Support the vent pipe with hangers at regular intervals or as required by local code;
the weight of the vent pipe must not rest on the water heater;
� Do not common vent nor connect any other appl iance to this water heater's venting
system;
� Vent and air intake pipe must be supported every 5 feet.
Navien and Direct Vent:
� All Navien water heaters are prepared at the factory to be direct vent (sealed
combustion) u nits which draw all of their required combustion air directly from
outside the building;
� All Navien water heaters use round 3" exhaust and round 3" air supply vent pipe. To
ensure the draw and exhaust of air directly to and from the outside, the exhaust vent
and air intake vent must be sealed airtight from unit collar to terminator;
� The air intake vent materials can be made of ABS, PVC, galvanized steel ,
corrugated aluminum or any other such materials.
material, ensu re there is no inadvertent crimping of, or damage to, the air intake vent.
Navien and Non-Direct Vent
� Navien recommends direct vent installations whenever possible to avoid
backdrafting cold air through the unit; if you cannot use direct vent, it is essential to
have an ample supply of make-up air.
� If at any time, the building experiences a negative pressu re situation when using a
non-Direct Vent unit, there is a possibility of back drafting cold, winter air from
outside through the heat exchanger of the water heater. This situation may freeze
the water heater's heat exchanger.
j u risdictions, negative pressu res in homes are not allowed .
balanced air supply, freezing of the heat exchanger will not occur.
� Since the cause of the backd rafting is insufficient make-up air within the house, this
is not a Navien water heater problem.
covered under warranty.
insists the use of direct vent.
According to the building codes in most
As such , any freezing damage is not
To avoid any such issues in colder climates, Navien
If you are using a corrugated
In a home with a well­