Valves; Manual By-Pass; Below Pool Installation; Flow Switch - Pentair ETi 400 Instructions D'installation

Section 2: Installation Instructions
20

VALVES

When any equipment is located below the surface of the pool or spa, valves should be placed in the circulation piping
system to isolate the equipment from the pool or spa. Check valves are recommended to prevent back-siphoning. Back-
siphoning is most likely to occur when the pump stops, creating a pressure-suction differential. Do NOT sanitize the
pool by putting chlorine tablets or sticks into the skimmer(s). When the pump is off, this will cause a high concentration
of chlorine to enter the heater, which could cause corrosion damage to the heat exchanger.
Exercise care when installing chemical feeders so as to not allow back siphoning of chemical into the heater, filters
or pump. When chemical feeders are installed in the circulation of the piping system, make sure the feeder outlet line
is down stream of the heater, and is equipped with a positive seal noncorrosive Check Valve, (P/N R172288), between
the feeder and heater.

MANUAL BY-PASS

Where the water flow rate exceeds the maximum 120 GPM,
a manual bypass should be installed. After installing the
valve, adjust the valve to bring the flow rate within the
acceptable range. Then remove the valve handle or lock
it in place to avoid tampering. See Figure 14.
Table 1: Heater Water Pressure.
ETi GPM (min. / max) Max. T (°F) / Min T (°F)
®
400
40 / 120
T
(*) Compare by observing the Temperature Pressure gauges
located inside the heater (see page 16), and the water inlet
temperature displayed on the Control Board LCD.

BELOW POOL INSTALLATION

If the heater is below water level, the pressure switch must be adjusted.
This adjustment must be done by a qualified service technician. See following CAUTION before installation.
The water pressure switch is set in the factory at 3.00 PSI (± 0.75 PSI). This setting is for a heater installed at pool level.
If the water pressure switch is more than 1 ft (30 cm) below or above the pool level, the water pressure switch must be
adjusted by a qualified service technician. Figure 4 on page 14.
If the water pressure switch is installed more than 3 ft (0.9 m) above the pool or more than 3 ft (0.9 m) below the pool
level, you will be beyond the limits of the pressure switch and a flow switch must be installed. Locate and install the
flow switch externally on the outlet piping from the heater, as close as possible to the heater. Connect the flow switch
wires in place of the water pressure switch wires.
ETi 400 High Efficiency Pool and Spa Heater Installation and User's Guide
CAUTION
35 / 25*
CAUTION
BELOW OR ABOVE POOL INSTALLATION

FLOW SWITCH

WARM WATER OUTLET
1. Set Manual By-Pass Valve.
2. Remove Handle.
WARM WATER TO POOL
COLD WATER INLET
COLD
WATER
FROM POOL
Figure 14.
Rev. C 4/2017