Section 2: Installation Instructions
28
COMBUSTION AIR SUPPLY
For indoor installation, the heater location must provide sufficient air supply for proper combustion and ventilation of the
surrounding area, see Table 3 below.
The minimum requirements for the air supply specify that the room in which a heater is installed should be provided with
two permanent air supply openings; one within 12 inches (30 cm) of the ceiling, the other within 12 in (30 cm) of the
floor for combustion air, in accordance with the latest edition of ANSI Z223.1, or the National Fuel Gas code, the CSA
B149.1, Natural Gas and Propane Installation Codes, as applicable, and any local codes that may apply. These openings
shall directly, or through duct, connect to outdoor air.
Air Supply Requirements Guide for the ETi
Minimum Net Free Open Area for Each Opening*
(Square Inches / Square Centimeters)
All Air From Inside Building
Model
Combustion
400 in
2
ETi 400
2580 cm
2
Table 3. Note (*) Area indicated is for one of two openings; one at floor level
and one at the ceiling.
CAUTION
Chemicals should not be stored near the
heater installation. Combustion air can be
contaminated by corrosive chemical fumes
which can void the warranty.
Note: For indoor installations where combustion air might be insufficient, see Direct Air Intake Duct
with 4 in PVC Pipe (Indoor Installation) on page 29 and 30.
ETi 400 High Efficiency Pool and Spa Heater Installation and User's Guide
All Air From Outside Building
Vent
Combustion
400 in
100 in
2
2
2580 cm
645 cm
2
2
®
400 Heater
NOTE *: Vent must be at least 2.4 m (8 ft) away from
nearest vertical surface. Vents extending 1.5 m (5 ft) or
more above the roof must be braced or guyed. Consult
your local code officials for detailed information.
Vent
100 in
2
645 cm
2
Rev. C 4/2017