Pentair ETi 400 Quick Start Guide

ETi® 400

HIGH EFFICIENCY HEATER

QUICK REFERENCE GUIDE

1

• Control Pad Overview

• Regular Maintenance

• Installation Requirements........2

• Frequently Asked Questions.....3

...............

...............

1
1

1

oint

187˚F (86˚C)

Thermal Fuses Activate

170˚F (77˚C)

SFS Activates

150˚F (66˚C)

Heating Pool

140˚F (60˚C)

Heating Spa

CONTROL PANEL OVERVIEW

Digital
Display

Set P
Controls

• POOL ON: Press button to base heater operation on Pool Temperature. LED
indicates heater is responding to Pool Temperature set point.

• SPA ON: Press button to base heater operation on Spa Temperature. LED indicates
heater is responding to Spa Temperature set point.

• HEATER OFF: Press button to switch o󰀨 the heater.

• HEATING LED: Illuminates when burner is active. Blinking LED indicates heater is

calling for heat but not ring. If LED remains illuminated, but burner fails to activate,

one of the Service LEDs will illuminate and indicate a system fault.

• SERVICE SYSTEM LED: Indicates insu󰀩cient water ow through heater. Ensure lter
and skimmers are clean. If LED remains illuminated, switch OFF heater and contact a
qualied service professional.

• SERVICE HEATER LED: Indicates a fault in heater or its controls. Switch OFF heater
and contact a qualied service professional.

TO VIEW ERROR CODES:

1. Press and release POOL ON and TEMP UP buttons simultaneously. The most

recent error code will display.

2. Use the TEMP UP or TEMP DOWN buttons to scroll through the last 5 error codes.

Note: To erase an error code, press POOL ON and SPA ON simultaneously while the

heater is o󰀨.

TO VIEW STACK FLUE TEMPERATURES:

1. Press and hold the POOL ON or SPA ON button for 5 seconds. Stack Flue 1 (SF1)

temperature will display, along with a dot in the upper left corner).

2. Press the TEMP UP button to display Stack Flue 2 (SF2) temperature.

REGULAR MAINTENANCE

For a list of all ETi heater replacement parts, and their
associated part numbers, consult the latest Pentair product
catalog or ETi 400 Installation and User's Guide.

START OF EVERY POOL SEASON:

1. Inspect heater panels
and venting system for
restrictions to air and

exhaust ow.

2. If installed within an

enclosure, ensure enclosure

air intakes are open and
clear of obstructions.

3. Test Pressure Relief Valve.
See image to the right.

4. Test Water Pressure

Switch. Refer to the ETi
400 Installation and User’s
Guide for specic test procedures.

EVERY 12 MONTHS:

1. Have a qualied service
professional clean and vacuum
out any soot or deposits from

Heat Exchanger. If necessary,

use a biodegradable descaler
solution to break up mineral
deposits.

Inspect the heat exchanger

insulation for damage.

2. Have a qualied service
professional inspect burner

spark electrode and ame

sensor for damage.

LEVER

UPWARDS

Spark
Electrode

Flame Sensor

INSTALLATION REQUIREMENTS

MAX AIR INTAKE AND EXHAUST LINE LENGTHS

4" Pipe

6" Pipe

Note: All horizontal sections must slope towards the heater 1/4" per foot. This
allows condensate to drain through the neutralizer cartridge properly.

120 ft

(36.3 m)

300 ft

(91.4 m)

# of 90º elbows

−

# of 90º elbows

−

VENTILATION REQUIREMENTS

• Schedule 40 PVC.
Schedule 80 CPVC
and stainless steel are
all approved venting
materials. PVC joints
must be glued in

compliance with National
Fuel Gas Code.

• If installed within an
enclosure and vented

outside, the termination

cap provided with the heater must be used.

If venting vertically, the termination cap may require a rain cap (not

provided).

AIR INTAKE REQUIREMENTS

• Max combustion intake length matches max venting length
caculated above.

• Intake and exhaust pipes must be minimum of 36"

(91.4 cm) apart.

• If using 4" pipe, Combustion Air Intake Kit (P/N 475971

-- sold separately) MUST be installed. Refer to the ETi
400 Installation and User’s Guide for specic installation

procedures.

x

x

12 ft

(3.7 m)

12 ft

(3.7 m)

# of 45º elbows

−

# of 45º elbows

−

Air Intake

x

x

Flue Exhaust

Air Intake Kit

(P/N 475971)

6 ft

(1.8 m)

6 ft

(1.8 m)

WATER FLOW REQUIREMENTS

• Front and back outer panels can be swapped,

allowing water connections to be oriented as
needed.

• To reduce ow rates, an external bypass valve is

required when water ow is above 120 GPM.

GAS REQUIREMENTS

• Bottom panels and internal gas valve can be swapped, allowing gas inlet to be

oriented as needed.

• Gas Supply Requirements

NATURAL GAS 4" WC 10.5" WC

PROPANE 4" WC 12" WC

Note: Maximum pressure change should not exceed 2" WC. Minimum running pressure

should not fall below 4" WC.

• Max Gas Supply Line Length

NATURAL GAS N/A 20 ft (6.1 m) 90 ft (27.4 m) 200 ft (61 m)

PROPANE 20 ft (6.1 m) 60 ft (18.3 m) 220 ft (67.1 m) 450 ft (137.2 m)

• Combustion Parameters

NATURAL GAS 7.8 - 9.2% 4.8 - 7.2%

PROPANE 9.6 - 10.2% 5.4 - 6.3%

MIN MAX

3/4" 1" 1-1/4" 1-1/2"

CO

2

O

2

OTHER INSTALLATION REQUIREMENTS

• 15 Amp Circuit Required.

• Heater produces 2-4 gallons (7.6 - 15.1 L) of condensate per hour. Condensate

neutralizers are not always required, but we strongly recommend installing a
Condensate Neutralizer Kit (P/N 475612).

2

FREQUENTLY ASKED QUESTIONS

• Which fuel does my heater use?

Inspect the heater's gas orice. The outer face of the gas orice will be marked with either

FN (Natural Gas) or NL (Propane).

• What certications does the ETi 400 meet?

The ETi heater is certied by The American Society of Mechanical Engineers (ASME). The heater
also complies with CSD-1 standard and CSA certied for ANSI Z21.56 /CSA 4.7. Certication sheets
are either included with the heater manual, or inside the packing slip attached to each heat exchanger.

• What makes the ETi 400 heat exchanger special?

The direct-re heat exchanger is made of extremely durable and highly corrosion-resistant titanium. The heat
exchanger's temperature rise is 30°F +/- 5°F (-1°C +/- 15°C).

• How e󰀩cient is the ETi 400 heater?

The ETi 400 has one of the highest thermal e󰀩ciencies in the pool industry. 96% of the heat generated during the

combustion process is transferred directly to pool water. This high e󰀩ciency improves your heat up time and reduces
your energy cost as shown by the formulas below:

TIME

ENERGY

COST

=

=

Pool/Spa Volume

Heater BTU

100,000

8.34 X ΔT

X

Heater BTU

Gas Price

X

X

X

Time

0.96

Time: Hours required to heat pool
Pool/Spa Volume: Volume of pool in gallons

ΔT: Desired temperature rise

Heater BTU: Heater BTU rating
Gas Price: Local gas price (therm/dollar)

• Will the outside of my heater become hot?

Thanks to the heater's high e󰀩ciency most of the heating capacity goes directly into your pool, but a small amount is expelled

as exhaust. This means the heater's plastic and metal outer surfaces remain close to room temperature.

3

WWW.PENTAIR.COM

All indicated Pentair trademarks and logos are property of Pentair Inc. or its global aliates in the U.S.A and/or other countries. Third party
registered and unregistered trademarks and logos are the property of their respective owners.

© 2020 Pentair. All rights reserved. This document is subject to change without notice.

*476253*

P/N 476253 REV. A 7/28/20