Noritz EcoTOUGH NRC661A-DV Installation Manual

Also see for EcoTOUGH NRC661A-DV: Owner's guide Owner's guide Owner's guide Replacement

18• Provide two permanent openings to allow cir-culation of combustion air.• Make each opening 180 square inches if theyprovide indoor air, and 100 square inches foroutdoor air.• If the unit is installed in a mechanical closet,provide a 24" (600mm) clearance in front ofthe unit to the door.• If combustion air will be provided through aduct, size the duct to provide 60 cubic feet offresh air per minute.• If the unit is installed in a mobile home, outdoorair must be supplied. The usage of the "-SV"conversion kit is prohibited.Combustion AirOpenings supplying indoor air9" (225mm)20" (500mm)9" (225mm)20" (500mm)▲The illustration is an example. Please check with the actual water heater about the position of piping, and form.Supply combustion air to the units as per the National Fuel Gas Code, ANSI Z223.1and in Canada, in accordance with the Natural Gas and Propane Installation CodeCSA B149.1.