17
Maintenance and Service
INDOOR INSTALLATION
Install 4" vent pipe directly on flue outlet.
The water heater should be located in an area where
enough air is available for proper combustion and
ventilation of the surrounding area. Follow the latest
edition of ANSI Z223.1 and any your local codes that
are applicable.
Eternal is a Category III vented appliance and
manufacturer's ventilation specifications should be
followed.
In general these requirements specify that if the unit
is installed in a confined space, there must be per-
manent air supply openings.
Combustion Air Supply:
Indoor Installation
Improper installation can cause nausea or as-
phyxiation from carbon monoxide and flue gases
which could result in sever injury or death. For
installation in altitudes above 4,500 feet, contact
the manufacturer for installation.
CAUTION
!
!
WARNING
Air supply from outside building:
When combustion air is supplied directly through an
outside wall such as intake louvers openings into the
dwelling, each opening should give a minimum free
area of one square inch per 15,000 Btu/hour of the
total input ratings of all appliances in the enclosed
area.
Air supply from inside building:
When combustion air is supplied from inside the build-
ing, each opening should give a minimum free area of
one square inch per 3,750 Btu/hour of the total input
ratings of all appliances in the enclosed area. These
openings should never be less than 40 sq.in.
64sq.in. each for GU32/501(11,12,21,22)1321
54sq.in. each for GU28/501(11,12,21,22)1281
48sq.in. each for GU26/501(11,12,21,22)1261
40sq.in. each for GU20/501(11,12,21,22)1201
MINIMUM RECOMMENDED AIR SUPPLY TO
WATER HEATER
INSTALLATION DIAGRAM
Water heater capacity
Outside air area
Inside air area
Max. 236,000 BTU
16 sq.in.
64 sq.in.
Max. 199,000 BTU
14 sq.in.
54 sq.in.
Max. 180,000 BTU
12 sq.in.
48 sq.in.
Max. 145,000 BTU
10 sq.in.
40 sq.in.
Water Heater Capacity Minimum Required Air Volume
Max. 236,000 BTU
3,150 cu.ft
Max. 199,000 BTU
2,655 cu.ft
Max. 180,000 BTU
2,400 cu.ft
Max. 145,000 BTU
1,950 cu.ft
The minimum required inside air volume should be 50
cu.ft per every 3,750 Btu/hour.
