Intellihot Legionator iL3.5 Quick start guide

Installation & Operational Manual
Legionator iL3.5 | iL6.0

Thank you for purchasing this Intellihot unit,
Our journey to create a better heating system began back in the winter of 2005,
when a tank-type water heater broke down and flooded my basement. By combining
the principles of a diesel engine’s robustness, robotics intelligence, and marine
environment durability, we set out to design a unit from the ground up ¬that would
outperform and outlast all others. Quickly, our goal grew from not just making a
better water heater, but creating an efficient and intelligent water heating and
delivery system.
Innovation is our hallmark and simplicity, efficiency, and durability are at the core
of every lntellihot product. Our water heaters utilize the best attributes of tank and
tankless – with intelligent logic and integrated recirculation. The result is a water
heating system capable of handling the extreme loads of commercial applications
with the preciseness needed for residential applications.
Our products are proudly engineered and built in Galesburg, Illinois making lntellihot
the first and only US based manufacturer of gas fired condensing tankless water
heating systems. Over the past eight years lntellihot has helped commercial
customers throughout the nation save thousands of dollars while eliminating
downtime. As we continue to expand our coverage across North America, we strive
to provide you with the same unmatched performance advantages and savings.
Our talented team of dedicated professionals is ready to assist you and help your
business succeed.
I thank you for purchasing our lntellihot products.
Sincerely,
Sridhar Deivasigamani
CEO, lntellihot Inc.

Table of Contents
1. General Information
1.1 Items Shipped With Water Heater..........4
2. Safety
2.1 Safety Signal Words.....................5
2.2 Installation Warnings ....................5
3. TechnicalSpecications
3.1 SpecicationsChart ....................8
3.2 Introduction ...........................9
3.3 WaterHeaterCharacteristics .............9
4. Installation Guide
4.1 General Guidance...................... 10
4.2 Before Installation ..................... 10
4.3 Wall Mounting ........................ 10
4.4 Seismic Bracing (optional)............... 12
4.5 Plumbing ............................ 12
5. Electrical Connection
5.1 ConnectionInstructions................. 14
5.2 Test Run............................. 16
6. Operation Instruction
6.1 Overall Dimensions......................17
6.2 Interface............................. 18
6.3 Operation ............................ 19
6.4 Auto Memory .........................20
6.5 Auto Resume .........................20
6.6 Auto Sleeping .........................20
6.7 Temperature Setting ................... 21
6.8 Ozonation............................ 21
6.9 Anti-Freezing ......................... 21
7. Maintenance
7.1 Pre-Filtration ......................... 21
7.2 After-Use Safety ...................... 21
7.3 Maintenance ......................... 21
8. Circuit Diagram
8.1 Model iL3.5/Il6........................22
9. Troubleshooting
9.1 Troubleshooting .......................23
9.2 ErrorCode ...........................24
10. Warranty
10.1 Warranty.............................25
11. Warranty Registration 29

Legionator iL3.5/iL6 General Information 4
Aug 2023 - Revision 00
1. General Information
1.1 Items Shipped With Water Heater
The items in the below table are shipped loose with the water heater.
No. Item Quantity
1Water heater 1 piece
2Wall-mounting fittings 1 set
3 Pre-filter 1 piece
4User´s manual 1 piece
5Warranty card 1 piece

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2. Safety
2.1 Safety Signal Words
DANGER
Indicates an imminently hazardous situation which, if not avoided, will result in death or
serious injury. This signal word is limited to the most extreme situations.
WARNING
Indicates a potentially hazardous situation which, if not avoided, could result in death
or serious injury.
CAUTION
Indicates a potentially hazardous situation which, if not avoided, may result in minor
or moderate injury.
NOTICE
Indicates that equipment or property damage can result if instructions are not followed.
SAFETY
INSTRUCTIONS
Safety instructions (or equivalent) signs indicate specific safety-related instructions
or procedures.
Note: Contains additional information important to a procedure.
2.2 Installation Warnings
WARNING
Read the instructions carefully, and understand all warnings and instructions
given in this manual before installing, operating, or servicing this water heater.
Failure to follow these warnings and instructions could result in property damage,
bodily injury, or death.
This manual must remain with the water heater. Make sure to Keep this manual in a
convenient place for future reference.

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WARNING
Make sure all electrical connections are turned OFF before the installation or service
of water heater.
The water heater should be installed by a licensed electrician, and plumber in
accordance with all national, state, and local electrical and plumbing codes.
Failure to follow the above-mentioned warning may result in property damage, serious
bodily injury, or death.
WARNING
Use only the voltage specified on the label for the model of this water heater.
To prevent accidental electrical shock, the water heater must be always installed to the
Ground Fault Circuit Interrupter (GFCI) outlet or circuit.
Failure to use the correct voltage shown on the model rating label could result in fire,
property damage, serious bodily Injury, or death.
WARNING
Improper installation and operation, or installation and service by an unqualified person
may cause property damage, serious body injury, or death.
CAUTION
IMPROPER INSTALLATION AND USE MAY RESULT IN PROPERTY DAMAGE
• The water heater must be installed in an indoor environment only.
• Do not install the water heater in a location where water might freeze due to external
temperature.
• If the water heater is not in use, turn OFF the main power switch and water supply
in the water heater.

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• If the supply cord is damaged, replace the supply cord in order to avoid damage to
the water heater.
• If the water inside the water heater is frozen, do not switch ON the water heater.
Make sure all the frozen water inside the water heater is unfrozen before you switch
ON the water heater. Failure to do so may result in serious damage to the water
heater.
• In order to avoid any damage to the water heater due to unintentional reset due to
power failure, do not use any external device, such as a timer, or another utility circuit
that is switched ON or OFF regularly in connection with the water heater.
• Refer to this manual for all installation and service instructions.
SAFETY
INSTRUCTIONS
1. This water heater is not intended for use by persons (including children) with
reduced physical, sensory or mental capabilities, or lack of experience, and
knowledge.
2. Do not allow children to play with the water heater.
Maximum inlet water pressure 1.03 MPa(150 PSI)
Minimum inlet water pressure 0.2 MPa (30 PSI)
3. The water inlet of this water heater must not be connected to any other water
heating system’s inlet water.
4. This water heater must be installed and serviced by a licensed electrician and
plumber, or a professional service technician in accordance with the national
electrical codes, local electrical and plumbing codes and regulations.
5. This water heater must be permanently connected to fixed wiring.
6. Do not install the water heater in a location where water might freeze due to
external temperature.
7. Do not install this water heater in locations where there is tinder or strong magnetic
fields in close proximity.
8. If the water inside the water heater is frozen, do not switch ON the water heater.
Make sure all the frozen water inside the water heater is unfrozen before you
switch ON the water heater. Failure to do so may result in serious damage to the
water heater.
9. In order to avoid any damage to the water heater due to inadvertent resetting of
the thermal cutout, do not use any external device, such as a timer, or another utility
circuit that is switched ON or OFF regularly in connection with the water heater.
10. Use the water heater for disinfection and water heating only. Do not use the water
heater for any other purpose.
11. Make sure to disconnect all the electrical connections to the water heater before
you clean, service, or remove the cover of the water heater.

Legionator iL3.5/iL6 Technical Specifications 8
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3. Technical Specifications
3.1 Specifications Chart
Model No. iL3.5 iL6
Rated voltage AC 120V AC 208V
Rated frequency 60Hz 60Hz
Rated power 3.5kW 6kW
Rated current 29 Amps
Phase Single phase
Minimum Field wire size 10 AWG
Recommended circuit breaker 40 Amps
Recommended grounding protection GFCI
Applicable water pressure 30 - 150 psi
Maximum water temperature 120°F
Maximum water flow rate 1.2 GPM
Activation water flow rate 0.2 GPM
Ozone concentration 0.02 - 0.04 ppm
Operation mode Electronic
Interface Touch panel
Display LED
Beeper YES
Inlet/outlet connection 3/8” Male
Mounting method Wall-mounting
Seismic Bracket Optional (included)
Ingress protection IPX1
Water heater size 115 x 152 x 371mm (4.5” x 6”x 14.6” H)
Gross weight 3.6 Kg (8 lbs)
Low Lead (Pb) NSF / ANSI 372
Safety Certifications
UL 60335-1, IEC 60335-2-35/
CSA C22.2 No. 60335-1, CSA C22.2 No.
60335-2-35
Note: Due to Intellihot´s policy of continuous product improvements the design and technical specifica-
tions are subject to change without notice.

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3.2 Introduction
Thank you for choosing INTELLIHOT water heater, the most advanced tankless water
heaters in the world today, that uses energy-saving quartz heating technology and
automatic ozonation technology. All our water heaters are manufactured with the
highest-grade materials and assembled professionally by qualified personnel.
INTELLIHOT tankless water heater do not store water like any other conventional
tank-type water heater. This water heater contains multiple high powered quartz tube
heating elements that are capable of heating water “on-demand” and continuously as
needed, so you will never have to worry about running out of hot water again.
The performance of the water heater is dependent on the inlet water temperature,
water flow rate, and the temperature set by the user. When the electrical power and
water flow are turned ON, the built-in digital microprocessor will check the temperature
sensor, flow sensor and current leakage sensor, if there are no errors found, the digital
microprocessor will automatically regulate the heating element to achieve a constant
water temperature or at the temperature set by the user. This process from the digital
microprocessor is designed to conserve energy.
This water heater must be installed in an indoor environment only. An outdoor
installation is permitted if it is mounted in a suitable enclosure that protects it from all-
weather elements. Extreme cold weather that causes the water in the water heater to
freeze may result in permanent damage and will void the warranty of the water heater.
3.3 Water Heater Characteristics
All our INTELLIHOT water heaters delivered to every customer are manufactured with
superior quality materials that has extended lifetime and modern designs that has great
look and feel to the water heater.
Our cutting-edge tankless water heater will provide the user with brand-new
experiences throughout the lifetime of the water heaters use, that includes:
- Completely safe and comfortable experience during every use
- Saving money (energy conservation) after every use
Characteristics of the water heater are highlighted as:
- Heats water within seconds
- On-demand water heating
- Automatic constant temperature control
- Energy efficient and small footprint
- Separate Water and Electricity connection prevents any electrical leakage
- Automatic ozonation process mode that kills pathogenic bacteria present in the
water
- Multiple safety protectors for the health safety of the user
- Compact design for convenient installation

Legionator iL3.5/iL6 Installation Guide 10
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4. Installation Guide
4.1 General Guidance
1. Electrical water heater should be installed by a qualified personnel and in
accordance with the national electrical codes, local electrical and plumbing codes
and regulations.
2. Make sure that the wire, fuse, circuit breaker, and watt-hour meter are applicable
to your water heater before installation. Please refer to Technical Specification
(3.1) in this manual.
3. Install the water heater in the vertical position as shown in the figure in this
manual. Do not install upside down or horizontally.
4. Make sure the electrical connections in the water heater are properly grounded.
4.2 Before Installation
1. Install the water heater on a smooth surface or platform.
2. Make sure to install the water heater away from strong vibrations.
3. This water heater must be installed in an indoor environment only. An outdoor
installation is permitted if it is mounted in a suitable enclosure that protects it from
all-weather elements. Extreme cold weather that causes the water in the water
heater to freeze may result in permanent damage and will void the warranty of
the water heater.
4.3 Wall Mounting
1. Place the wall-mount in a proper position and use a pencil to mark the holes as
shown in figure 1.
2. Use an appropriate tool to drill the holes on the exact marked position as shown
in Figure 2.
3. Install and fasten the holes with appropriate plastic inserts as shown in Figure 3.
4. Place the water heater on the mounting brackets and fix the wall-mounting with
appropriate screws as shown in in Figure 3.

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T
ongue insertion
Locking hook
2-position orientation
Figure 1
Drill
Wall
Figure 2
Plastic insert
Hole
Figure 3

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Aug 2023 - Revision 00
4.4 Seismic Bracing (Optional)
1. An additional bracket is provided for seismic bracing as shown in Figure 4.
2. This part is OPTIONAL to install.
3. Seismic bracing is recommended for safe installation if the water heater is being
operated in an earthquake-prone area.
Figure 4
4.5 Plumbing
CAUTION
If you are replacing an existing water heater, replace the old hose sets with the new
hose sets.
WARNING
There is no internal pressure protection devices built in. Please make sure that there is
an external protection is added to keep the water pressure within 30 - 150 PSI (0.2 -
1.0MPa). .
1. Use cold water to flush any debris present in the water line of the water heater
before use.
2. Install a manual shut off valve (not supplied with the water heater) and pre-filter
to prevent the entry of any particles that may clog or damage the internal parts of
the water heater. Manual shut off valve is required on both the water inlet and on
the water outlet as shown in figure 5.

13 Legionator iL3.5/iL6 Installation Guide
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3. The water inlet and the water outlet shall be identified according to the indications
or marks on the water heater. If colors are used to indicate then water inlet and
water outlet, blue color should be used for the water inlet and red color for the
water outlet.
4. The water heater may not function if the water inlet and the water outlet are not
fitted properly as shown in Figure 5.
5. Do not use plumbing cement on water connections. If necessary, use only thread
compound or pipe thread sealant or sealing tape as required.
6. Do not solder any external fittings to the water heater. This will damage internal
sensors or components and void the warranty.
7. A Temperature-Pressure Relief (TPR) installation is not mandatory to your
water heater, please refer to your local jurisdiction or local body to confirm the
requirement for TPR installation on the water heater at your location.
8. Connect the water hose to the outflow pipe of the water heater and connect the
faucet sink to the water hose as shown in Figure No 5.
9. Use the pre-filters provided by the Intellihot only, prevent any blockages in the
water pipelines.
10. Make sure all the water heater fittings are secured properly and make sure there
are no loose fittings of any parts of the water heater.
11. The Specification of pipes is G (BSPP) 3/8 inches.
Figure 5

Legionator iL3.5/iL6 ElectricalConnection 14
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5. Electrical Connection
5.1 Connection Instructions
WARNING
This water heater must be installed and serviced by a licensed electrician and plumber,
or a professional service technician in accordance with the national electrical codes,
local electrical and plumbing codes and regulations.
WARNING
Improper installation and operation, or installation and service by an unqualified person
may cause property damage, serious body injury, or death
.
WARNING
If the Field supplied cord is damaged, it must be replaced by qualified persons in order
to avoid hazard
.
WARNING
Make sure the electrical supply to the water heater is turned OFF before installation or
service of the water heater. SERIOUS BODILY INJURY OR DEATH COULD OCCUR IF
YOU IGNORE THIS WARNING.
WARNING
A properly sized Circuit breaker or other means for disconnection from the supply
mains must be incorporated in the fixed wiring in accordance with the local wiring
rules.
1. Use only the voltage specified on the label for the model of this water heater.
Make sure the water heater is always connected to the Ground Fault Circuit
Interrupter (GFCI) outlet or circuit in order to prevent accidental electrical shock.
2. Make sure the electrical power at your location meets the requirements as shown
in the technical specifications (3.1) given in this manual.

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3. Special attention should be given to the following before electrical connections
are installed:
a. Polarity of all electrical connections
b. Available Current voltage in the connecting wires
c. Rated current voltage of fuse or circuit breaker
d. Maximum current voltage (capacity) of watt-hour meter
4. Steps of electrical connection:
a. Unfasten the cord grip as shown in Figure 6.
b. Insert the field supplied power cord wire inside the hole of the cord grip and
route the power cord through the water heater as shown in the Figure 6.
c. Remove the screws from the wiring cover to access the electrical connections
as shown in Figure 7.
d. Gently pull the terminal block outside and connect the wires to corresponding
polarities.
e. Gently push the back cover of the water heater and re-fasten the screws on
the wiring cover.
5. Make sure all the wire ends, terminal blocks and circuit breakers are secured
properly.
6. Make sure all the screws are fastened and secured.
Figure 6

Legionator iL3.5/iL6 ElectricalConnection 16
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Figure 7
5.2 Test Run
1. Make sure to maintain the below checklist after power supply and water supply
are turned ON:-
a. Make sure wall-mounting is fitted in the correct position.
b. Make sure all plumbing instructions are completed.
c. Make sure all the electrical connections are secured.
d. Make sure there is no error code on the display screen.
e. Make sure there is no water leakage.
f. Make sure all screws and fittings are tight and secure.
2. Open the water source and allow the water to flow for a minimum of 2 minutes.
This will purge the air from the water lines. This step is mandatory before switching
ON the power of the water heater.
3. The water heater is ready for use.

17 Legionator iL3.5/iL6 Operation Instruction
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6. Operation Instruction
6.1 Overall Dimensions
The dimension of the water heater is as shown in Fig. 8, the unit of measurement is
in millimeters (inch values are in bracket).
The User interface presents the MULTIFUNCTION button is as shown in Fig. 9
Figure 8
Figure 9

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6.2 Interface

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6.3 Operation
For the convenience of consumers, the water heater adopts ONE-BUTTON
OPERATION, which consists of 6 steps by the way of moving up or down.
Your water heater is ready to use when the electricity and water connections are
turned ON and the water heater enters Standby mode. There won’t be any displays
right now.
•
Press MULTIFUNCTION button again,
you can choose the temperature mode
At this time, you can choose temperature
unit by pressing UP / DOWN button.
UP: temperature display in degree
Fahrenheit (°F)
DOWN: temperature display in degree
Celsius (°C)
Press MULTIFUNCTION button again,
you can choose working of ozonation
At this time, you can choose working
or not working of ozone generator by
pressing UP / DOWN button.
UP: automatic working of ozone
generator (O3 Auto)
DOWN: Turns off ozone generator (O3
Off)
•
Press MULTIFUNCTION button and hold
for 5 -10 seconds, the appliance will cut
off automatically, and there will be no
displays

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6.4 Auto Memory
When the water heater restarts after an intermittent shut OFF due to power failure,
the automatic memory function in the water heater will re-set the water heater to its
previous (most recent) operational mode or user settings.
6.5 Auto Resume
When there is a power outage and/or water supply outage, the water heater will shut
OFF automatically for safety and protection of the water heater. When the power
supply and/or water supply resumes, the water heater will automatically re-start on
its own. There is no need to press the MULTIFUNCTION button to restart the water
heater.
6.6 Auto Sleeping
After a total of 45-minutes continuously running and heating the water, the auto sleep
function will cause the water heater to shut down automatically for safety reasons. In
these conditions, the user can press the MULTIFUNCTION button to restart the water
heater.
6.7 Temperature Setting
Make sure all the connections and fittings of the water heater are secured. Purge all
the air from the water heater before switching the ON button.
The flow of water activates the flow sensor to send signals to the digital microprocessor
in the water heater that controls the heating element to heat the water.
Use the temperature settings to increase or decrease the water temperature and/or
water flow rate in your water heater (by using the field supplied manual shut-off valves
as per Figure 5).
Press UP or DOWN on the mode buttons to set your required water temperature.
When the water flow rate reaches the maximum heating capacity of the water heater,
a maximum temperature will be achieved based on the water flow rate and the rated
power of the heater. When the excessive water flow rate is gradually reduced the
water heater will achieve the Set-Point (SP) temperature.
When the water flow rate is cut-off, the flow sensor sends the signals to the digital
microprocessor to turn OFF the heating element, during this time, the water heater
will be on Standby mode until the flow sensors sends back signals to the digital
microprocessor to turn ON the heating element in order to continue the flow of hot
water, as needed by the user.