Plumbing Connections; Water Connections - Pentair ETi 400 Instructions D'installation

PLUMBING CONNECTIONS

The heater has the unique capability of direct schedule 40 PVC plumbing connections. A set of bulkhead fittings is
included with the heater to ensure conformity with Pentair's recommended PVC plumbing procedure. Other plumbing
connections can be used. See Figure 12 for plumbing connections.
CAUTION
Before operating the heater on a new installation, turn on
the circulation pump and bleed all the air from the filter
using the air relief valve on top of the filter. Water should
flow freely through the heater. Do not operate the heater
unless water in the pool/spa is at the proper level. If a
manual by-pass is installed, temporarily close it to ensure
that all air is purged from the heater.

WATER CONNECTIONS

The heater requires proper water flow and pressure
for its operation. See Figure 13 for the recommended
installation. The filter pump discharges to the filter,
the filter discharges to the heater, and the heater
discharges directly to the pool or spa.
A manual bypass valve should be installed before
the heater when the pump flow exceeds 120 GPM
(454 LPM ). See WATER FLOW RATE Table 1
on page 20 for setting of the manual by-pass valve.
Make sure that the outlet plumbing from the heater
contains no shut-off valves or other flow restrictions
that could prevent flow through the heater (except
for pool installations as noted below, or winterizing
valves where needed). To switch flow between the
pool and spa, use a diverter valve. Do not use any
valve that can shut off the flow.
Install the chemical feeder downstream of the
heater. Install a chemical resistant one-way check
valve between the heater and the chemical feeder
to prevent back-siphoning through the heater
when the pump is off.
NOTICE: If the heater is plumbed in backwards, it will cycle continuously. Make sure piping from filter is not reversed
when installing heater.
Connect the heater directly to 2 in PVC pipe, using the provided unions. Heat sinks are not required. The low thermal mass
of the heater will prevent overheating of the piping connected to the pump even if the heater shuts down unexpectedly.
Occasionally a two-speed pump will not develop enough pressure on the low speed to operate the heater. In this case, run
the pump at high speed only to operate the heater. If this does not solve the problem, do not try to run the heater. Instead,
correct the installation.
Do not operate the heater while an automatic pool cleaner is also operating. If the circulation pump suction is plugged
(for example by leaves), there may not be adequate flow to the heater. Do not rely on the pressure switch in this case.
Rev. C 4/2017
Section 2: Installation Instructions
HEATER
TO
POOL
Figure 12.
Main
Drain
Pool
From Pool
Figure 13.
ETi 400 High Efficiency Pool and Spa Heater Installation and User's Guide
INLET
OUTLET
FROM
FILTER
FILTER
MANUAL
BY-PASS
GATE
VALVE
FROM
POOL
3-Way
Chlorinator
Valve
Heater
Spa
Pump
3-Way
Valve
19
PUMP
Check Valve
Filter
3-Way
Valve