Section 2: Installation Instructions
32
HORIZONTAL OR VERTICAL VENTING (CATEGORY IV) - POSITIVE PRESSURE
(See Figure 26, page 34 and Figure 27, page 35)
Vent the heater either horizontally or vertically using the 4 in Vent Adapter that is provided with the heater. Install the
vent pipe in accordance with local codes and the provisions of the National Fuel Gas Code, ANSI Z223.1 (U.S.),
or the standards CSA B149.1, Natural Gas and Propane Installation Codes (Canada), and the vent manufacturer's
instructions. Do not use a draft hood with this heater. Install the vent according to the vent manufacturer's
detailed instructions. Note: Maintain clearance between the vent pipe and combustible surfaces according to the
vent manufacturer's instructions and code requirements. Do not place any insulating materials around the vent
or inside the required clear air space surrounding the vent. See Table 6 for maximum permissible vent lengths.
Each 90° elbow reduces the maximum horizontal vent run by 12 ft and each 45-degree elbow in the vent run
reduces the maximum vent run by 6 ft. See the Table 6 below for the maximum vent lengths using 90° elbows.
®
The ETi
400 heater is a Category IV appliance
The ETi 400 heater requires a 4 in special gas approved Category IV vent pipe and is a forced-draft pool and
spa heater which uses positive pressure to push flue gases through the vent pipe to the outside. Flue gases under
positive pressure may escape into the dwelling with any cracks or loose joints in the vent pipe, or improper
vent installation. The vent pipe must be of a sealed-seam construction, such as those listed for use with Category
IV Appliances. Vent pipe construction will be of UL 1738 approved non-corrosive material, such as non-metalic
PVC schedule 40 per ASTM D2665, CPVC schedule F441 or stainless steel such as AL 29-4C per UL 1738 in USA.
In Canada must comply with ULC-5636 code requirements. The 4-in exhaust socket is CPVC. A condensate trap is
required.
Note: To solvent weld the PVC vent pipe to the CPVC exhaust socket use an approved industry standard
primer and cement solvent specifically intended and marketed for PVC/CPVC joints, consult the adhesive
manufacturer for details.
The use of Approved thimbles, roof jacks and/or side vent terminals are required; and the proper clearances to
combustible materials must be maintained in accordance with type of vent pipe employed—in the absence of a
clearance recommendation by the vent pipe manufacturer, the requirements of the Uniform Mechanical Code should
be met. The ventilation air requirements for the heater are shown on page 35 and 35. It is recommended that use of a
condensate trap in the vent run close to the heater may be necessary in certain installations such as cold climates. Horizontal
vents 4 in (25.4 mm) or less in length do not require a condensate tee. The heater is suitable for through-the-wall
venting.
(*) Special Gas Vent (Vertical or Horizontal)
Maximum length in Feet (m)
No. of 90° Elbows
4-in (10 cm) pipe 6-in (15 cm) pipe
0
120 ft. (36.6 m)
1
108 ft. (33 m)
2
96 ft. (29.3 m)
3
84 ft. (26 m)
4
72 ft. (22 m)
Table 6.
ETi 400 High Efficiency Pool and Spa Heater Installation and User's Guide
NOTE
(*)
with vent manufacturer's instruction, and local and national
codes. Horizontal vents 3 ft (1M) or less in length do not
require a condensate tee, but must slope down toward the
300 ft. (91.4 m)
heater at 1/4 in to the foot (2 cm / m) to allow condensate to
288 ft. (87.7 m)
drain through the neutralizer cartridge.
276 ft. (84.1 m)
264 ft. (80.4 m)
252 ft. (76.8 m)
Minimum vent length is 1 ft (.34M), or in accordance
Rev. C 4/2017