COMBUSTION AIR SUPPLY
Each 90-degree elbow reduces the maximum horizontal PVC air intake duct run by 12 feet and each
45-degree elbow in the PVC air intake duct run reduces the maximum run by 6 feet. See the Table 5 on
page 28 for the maximum lengths using 90-degree elbows.
Chemicals should not be stored near the heater installation. Combustion air can be contaminated by corrosive
chemical fumes which can void the warranty.
Corrosive Vapors and Possible Causes
Area
Chlorinated
swimming
pools and spas
New construction
and remodeling
areas
Beauty parlors
Refrigeration plants
or various industrial
finishing and
processing plants
Dry cleaning and
laundry areas
Table 5.
Rev. C 4/2017
(CONTINUED)
Pool or spa cleaning chemicals. Acids, such as hydrochloric or muriatic acid.
Glues and cements, construction adhesives, paints, varnishes, and paint and varnish
strippers. Waxes and cleaners containing calcium or sodium chloride.
Permanent wave solutions, bleaches, aerosol cans containing chlorocarbons or
fluorocarbons.
Refrigerants, acids, glues and cements, construction adhesives.
Bleaches, detergents, or laundry soaps containing chlorine. Waxes and cleaners
containing chlorine, calcium or sodium chloride.
ETi 400 High Efficiency Pool and Spa Heater Installation and User's Guide
Section 2: Installation Instructions
NOTE
CAUTION
Likely Contaminants
31