Navien NFC-250/175H Installation Manual page 89

To avoid moisture and frost build-up and to
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maintain clearances to openings on adjacent
homes, 45° elbows, 90° elbows, or tees may be
attached to the end of the termination vent pipe
to direct the exhaust plumes away from buildings,
as long as the total allowable vent lengths,
maximum number of elbows, and distances to air
intake restrictions are observed.
If the boiler units will be installed in areas where
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snow is known to accumulate, protect the vent
termination from blockage. Provide a minimum of
1 foot (30 cm) clearance from the bottom of the
exhaust of the expected snow accumulation level.
Snow removal may be necessary to maintain
clearance.
Ensure that the vent termination is at least 12 in
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(300 mm) above ground, 12 in (300 mm) above
the highest anticipated snow level, or as required
by local codes, whichever is greater.
Support the vent pipe with hangers at regular
●
intervals or as required by local codes.
The vent for this appliance shall not terminate
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over public walkways; or near soffit vents or crawl
space vents or a nuisance or hazard or cause
property damage; or where condensate or vapor
could cause damage or could be detrimental to
the operation of regulators, relief valves, or other
equipment.
Adequate Installation Clearances
CAUTION
Do not install the boiler on carpeting.
Install the boiler in an area that allows for service
and maintenance access to utility connections,
piping, filters, and traps. Based on the installation
location, ensure that the following clearances are
maintained:
Top
Back
Side
Bottom
Clearance from: Indoor Installation
Top 9 in (229 mm) minimum
Back 0.5 in (13 mm) minimum
Front 4 in (100 mm) minimum
Sides 3 in (76 mm) minimum
Bottom 12 in (300 mm) minimum
CAUTION
It is necessary to leave clearance for service
access.
Installing a Common Vent System
Side
Front
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