Keltech HL Series User manual

729 S. Grove St., Delton, MI 49046
TEL: [phone] • 800-999-4320 FAX: [phone]
[email protected] • www.keltech-inc.com
Installation
215-1823 Rev. A; ECN 150023
© 2015 Keltech
Page 1 of 20 11/24/2015
HL-Series
Tankless Heater Models
HL05
HL06
HL10 & L10
HL12
HL15 & L15
HL18 & L18
Voltage options:
208V Single and Three Phase
240V Single and Three Phase
277V Single Phase
380V Single and Three Phase
415V Single and Three Phase
480V Single and Three Phase
Table of Contents
Pre-Installation Information ......................... 2-3
Storage Instructions .................................3
Mounting Heater....................................4
Plumbing Installation .............................. 5-6
Electric Installation ..................................7
Start Up Check List .................................8
Start Up ..........................................9
Digital Controller Operation ....................... 10-11
Operational Tests ............................... 12-13
Product Options ...................................13
Maintenance......................................14
Troubleshooting ................................ 15-16
Special Installation & Operating Instructions .......... 17-20

2
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
DANGER
Tipover hazard. System can crush you resulting in serious injury or death. Read and follow precautions in this
installation manual that accompanied the heater for instructions on how to safely transport and anchor heater.
Do not transport with the heater in the vertical position. This heater is top heavy and should not be placed in
the vertical position until the site is prepared to anchor to the wall.
WARNING
Read this manual BEFORE using this equipment. Failure to read and follow all safety and user information
could result in death, serious personal injury, minor burns, property damage, or damage to the equipment.
Keep this Manual for future reference. Failure to comply with proper installation and maintenance instructions
could contribute to the heater’s failure.
ASSE standard 1016, 1069 or 1070 listed devices should be used at fixtures to prevent possible injury. Severe
bodily injury including scalding, chilling, and/or death may result depending upon system water pressure
changes and/or supply water temperature changes.
For safe operation of the heater, observe all warning labels as indicated.
Water heater system under pressure. Do not open enclosure while in operation.
These heaters should never be used to provide “anti-scald” or “anti-chill” service.
Hazardous voltage inside enclosure may result in serious burns or death. Disconnect power supply before
performing any work in the enclosure.
Failure to ground this system may result in death or serious injury.
Make sure that all water supply lines have been flushed and then completely turned off before beginning
installation. Debris in supply lines can cause valves to malfunction.
CAUTION
Hot pipes! Do not touch. May cause minor burns.
NOTICE
These heaters do not provide protection from supply or outlet pipe freezing.
Consult local building and plumbing codes prior to installation. Should these codes differ from the information
in the Manual, follow the local codes. Inquire with governing authorities for additional local requirements.
Regular checking and cleaning of the heater’s internal components and check stops is necessary for maximum
life and proper product function. Periodic inspection and yearly maintenance by a licensed contractor is
required. Corrosive water conditions, and/or unauthorized adjustments or repairs could render the heater
ineffective for its intended service. Frequency of cleaning and inspection depends upon local water
conditions. For heaters with adjustable output temperatures, check and adjust as needed at initial installation
and on a quarterly basis.
IMPORTANT
Read this entire installation manual to ensure proper installation. When finished with the installation, file this
manual with the owner or maintenance department. Compliance and conformity to local codes and ordinances
is the responsibility of the installer. Product warranties may be found under “Products” on our Web site at
www.keltech-inc.com.
Separate parts from packaging and make sure all parts are accounted for before discarding any packaging
material. If any parts are missing, do not begin installation until you obtain the missing parts.
A qualified plumber or electrician should install and service this system. Install system according to these
instructions and in compliance with national and local codes.

3
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Pre-Installation Information
General Information
The Keltech Tankless Water Heater provides instant and precise temperature-controlled hot water. To insure proper
performance, install the heater according to the following installation instructions and in compliance with applicable
national and local codes.
Keltech can supply heaters for most commercial and industrial hot water applications. Flow rates and temperature
figures are important for proper sizing. If needed to meet certain temperature demands, flow control devices are
readily available. See temperature rise table for specifications. Contact KELTECH, INC. for further information on
available flow control devices.
Operation and Setup
HL-Series heaters supply an unlimited amount of hot water with specific flow and temperature rise capabilities. These
heaters are energy efficient, reliable, and provide optimum performance in the most demanding applications.
Application Specific Requirements
The HL-Series can be used in many different applications that require custom tuning for specific applications to
maximize performance of the heater.
For use in a recirculation loop, the incoming loop temperature should not exceed 140°F (60°C).
For applications utilizing quick close valves or solenoid valves, it is important to install a hammer arrestor or surge
tank close to the point of use to absorb pressure spikes.
Installation Considerations
Maximum operating pressure: 150psi.
Standard flow activation: 0.5 gpm
Certifications
Keltech Electric Tankless Water Heaters are certified by ETL to UL499 and third party certified to NSF/ANSI 372.
WARNING For safe operation of the heater, observe all the warning labels as indicated.
Storage Instructions
NOTICE! Keep Keltech Electric Tankless Water Heaters stored in original packaging until installation.
Recommended storage criteria:
Store Keltech Electric Tankless Water Heaters where temperatures exceed 35ºF (2º C) at all times.
Indoor storage is required.
Minimize excessive on-site transport to reduce risk of shock and impact damage.
Packaging
Box dimensions approx: 30" x 15" x 6" (762mm x 381mm x 152mm)
All boxes must be stacked evenly and horizontally.
Safety issues related to packaging:
• Product should be transported with the care associated to packages labeled “FRAGILE” even if packaging is not
marked accordingly.
• Standard safety procedures for forklift transport and large items less than 1000lbs should be followed at all times.

4
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Mounting Heater
1
WARNING HIGH VOLTAGE SHOCK. Disconnect power supply before performing any work inside
the heater enclosure.
For best results, install heater as close as possible to the point of use.
Installation should be performed by a qualified plumber or electrician.
Long pipe runs are not recommended. A heat loss of 1°F for every 10ft (3 meters) of uninsulated
pipe can occur.
When determining a mounting location, give consideration to the location of the main electrical panel
and ensure accessibility of the cabinet enclosure cover and other plumbing for service/maintenance.
Side View - Wall Mounting Holes (NEMA 1)
ASet heater in a vertical, upright position
with the water inlet and outlet located at
top.
Depending on the application, the unit
may also be installed rotated clockwise
90° with the inlet and outlet to the right.
B
Mount heater to the wall using the (4)
mounting brackets on the back of the
enclosure. Bolt the heater to the vertical
surface. Mounting holes are designed for a
maximum bolt size of 1/4" bolt diameter.
C
Install the pressure and temperature relief
valve on hot water outlet immediately
following the union.
NOTICE! Valve must empty into a drain.
Heater should be mounted on a vertical
surface and securely hold a minimum of
45 pounds. Use lead or plastic anchors
when mounting directly onto concrete or
block walls.
13"
(330)
2.75" (70)
13.5"
(343)
23"
(584)
14"
(356)

5
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Plumbing Installation
2
B
Install one union on the water inlet side of
the heater. Install one 100 Mesh (150 micron)
Y-strainer above (upstream of) union.
Install one union on the water outlet side of
the heater. Install one P&T Relief Valve above
(downstream of) union.
For Non-Teflon heaters: with the heater lying flat,
solder one half of each union to the inlet and outlet
tubes.
Install the pressure relief valve (150 psi) and outlet
plumbing of heater per local code requirements
and route relief valve discharge to drain. Make
sure no shutoff valve is between the relief valve
discharge and the drain. Install hammer arrestor.
Ensure plumbing is secure and not subject to
vibrations.
WARNING The heater must be lying flat
to do any soldering on the inlet or outlet
tubes. Soldering on the inlet or outlet tubes
in the upright position can damage internal
components. Damage caused by dripping
solder or flux can make your heater inoperable.
CUse 3/4" hard copper tubing or pipe as needed.
AInstall shutoff valve above (upstream of) the heater
inlet.
CAUTION To avoid damage to the electronics or
internal wiring, do not perform any brazing
or sweat soldering inside the enclosure.
NOTICE! Failure to install proper filtration may result in
a flow switch malfunction.
NOTICE! To avoid water damage, install a drain
pipe from the pressure relief valve to an
unrestricted drain per local code requirements.
If end use fixture is not at the highest point in
the plumbing loop, then an automatic air vent
valve must be added at the highest point in the
system or at any drop to eliminate trapped air.
Components Needed:
• (2) Union 3/4"
• Shutoff Valve
• Pressure and Temperature Relief Valve (150 psi)
• Y-Strainer (100 mesh) or Inline Filter (150 microns)
• (2) Gate or Ball Type Valves
• Drain pipe
• Elbows, nipples and fittings as needed
• Water hammer arrestor (recommended)
Dimensions,
Plumbing
and Electrical
Configurations
NEMA 1 2" (51)
HL Outlet 3/4" Copper
11"
(279)
HL Inlet 3/4" Copper
1.3"
(33) 1.5"
(38)
1.3"
(33)
4.7"
(119)
1.1"
(28) Pressure Relief
Valve (if Local Code
Requires)
Outlet
Inlet, 3/4"
Copper
Inlet, 3/4"
Copper
Threaded Unions
Y-Strainer, 100 Micron
Recommended
Ball or Gate Valves
Inlet
Power Entrance
Suggested Installation
Configuration
Components provided by installer
unless otherwise specified.
Reference the product options
sections or contact your local
Bradley Representative for
product options.
L Series heaters have 1/2" inlet and outlet and require 1/2" copper tubing. 3/4" threaded
unions are used for the L Series with NEMA enclosure.

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HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Plumbing Installation cont...
2
25-1/2"
(648)
3/4" Female
NPT Outlet 11"
(279) 3/4" Female
NPT Inlet
2-5/16"
(59)
2"
(51)
24"
(610)
14-1/2"
(368)
16"
(406)
7" (178) N4
8-3/4" (222) N4X
Dimensions,
Plumbing
and Electrical
Configurations
NEMA 4/4X

7
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Electric Installation
3
B
NEMA 1: A pre-cut hole is already sized
for conduit connection. Skip to step C.
NEMA 4/4X: Using a hole punch,
cut a hole the proper size for conduit
connection; large enough for the wire size
for each heater. The connectors need to
be rated NEMA4/4X to ensure proper
sealing of the enclosure.
A
For NEMA 1 enclosures, remove the four
screws and take the bottom cover off.
For NEMA 4/4X enclosures, open the
enclosure door.
CRun wires through the appropriate size
conduit.
DConnect wires to the system terminal
block inside the enclosure.
EConnect the ground wire to the stud
provided with the “Ground” label beneath it.
NOTICE! Any option that requires field wiring
must be done with a wire rated for
the maximum voltage of the heater.
NOTICE! Use a three for a single phase or a
four core cable for three phase from
an approved isolating two or three
pole switch or circuit breaker to the
terminal block of the heater.
NOTICE! Make sure the electrical cable is the
correct size to carry 100% of the full
load current. See table for proper
wire sizes.
WARNING Install product to rated line voltage
in accordance to current local and
national codes and regulations.
WARNING All Keltech heaters must be fused
in accordance with National
Electric Code (NEC) for the full load
amperage listed on the nameplate
rating for each heater.
WARNING Failure to properly ground the unit(s)
per the National Electric Code could
result in injury or death.
ELECTRICAL SPECIFICATIONS FOR HEATER
(Single Phase)
Model Voltage Amps kWatts Min Wire
Size
HL060/480D 480 13 6 12 AWG*
HL120/480D 480 25 12 8 AWG*
HL180/480D 480 38 18 6 AWG*
HL060/415D 415 6 4 12 AWG*
HL120/415D 415 12 9 12 AWG*
HL180/415D 415 19 13 10 AWG*
HL060/380D 380 6 4 12 AWG*
HL120/380D 380 11 8 12 AWG*
HL180/380D 380 17 11 12 AWG*
HL060/277D 277 22 6 10 AWG*
HL120/277D 277 43 12 6 AWG*
HL180/277D 277 65 18 3 AWG*
HL050/240D 240 21 5 10 AWG*
HL060/240D 240 25 6 8 AWG*
HL100/240D 240 42 10 6 AWG*
HL120/240D 240 50 12 4 AWG*
HL150/240D 240 63 15 3 AWG*
HL180/240D 240 75 18 3 AWG*
HL050/208D 208 24 5 10 AWG*
HL060/208D 208 29 6 8 AWG*
HL100/208D 208 48 10 4 AWG*
HL120/208D 208 58 12 4 AWG*
HL150/208D 208 72 15 3 AWG*
HL180/208D 208 87 18 3 AWG*
* Based on the NEC Table 310.15 for 75°C insulated copper wire @ 30°C
Ambient. Aluminum wire requires larger gauges.
ELECTRICAL SPECIFICATIONS FOR HEATER
(Three Phase)
Model Voltage Amps kWatts Min Wire
Size
HL103/480D 480 13 10 12 AWG*
HL183/480D 480 22 18 10 AWG*
HL103/415D 415 10 7 12 AWG*
HL183/415D 415 19 13 10 AWG*
HL103/380D 380 10 6 12 AWG*
HL183/380D 380 17 11 12 AWG*
HL153/240D 240 36 15 6 AWG*
HL183/240D 240 43 18 6 AWG*
HL153/208D 208 42 15 6 AWG*
HL183/208D 208 50 18 4 AWG*
HL103/208D 208 28 10 8 AWG*
Not all available (optional) voltages are listed in table.

8
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Start Up Check List
4
Plumbing
System is set in a vertical, level, and upright position with the outlet located at the top (installing the heater on
its back, for example, will trap air in the heat exchanger). System is mounted to the wall using the (4) mounting
holes located on the back of the enclosure.
Confirm installation of shutoff valve above (upstream of) the union on the inlet connection. Confirm installation of
a Y-strainer (100 mesh screen) or inline filter (150 micron) between the inlet shutoff valve and the heater.
Pressure and temperature relief valve is installed on tepid water outlet immediately following the union. No valve
or restriction is between the relief valve and the system or the relief valve and drain. Shutoff valve is installed
after pressure and temperature relief valve on outlet if required by local or national plumbing codes.
If the hot water process is not at the highest point in the plumbing loop, then an automatic air vent valve must be
added at the highest point in the system plumbing loop to eliminate trapped air.
Electrical
Verify supply voltage matches the indicated voltage on the Serial Tag. Serial Tag is located within the heater
enclosure on the upper left corner of the back plate (mounting plate).
Appropriate conduit is installed properly, secured and sealed to unit enclosure per NEC and hazard
location requirements. If the heater is installed in a classified area, it must be ordered with the correct hazard
location product options (ex. EXP2).
Appropriate conductors for unit routed through conduit and secured to power block inside the enclosure
(See Electrical Specifications chart). All electrical is installed in accordance with national and local electrical
codes, including fuse size and rating.
Appropriate earth ground is installed to the lug provided within the enclosure.

9
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Start Up
5
ASlowly turn on water supply to the unit
with the enclosure cover open and the
breaker in the off position.
CTurn off the connected process and
check the entire system to verify leak-free
installation.
DSecure the enclosure cover (standard
NEMA 1) or door (NEMA 4/4X).
F
Energize the electrical service to the unit
by switching on the two or three pole
switch or circuit breaker. Unit is now in
the ready state.
B
Slowly turn on the water outlet valve,
activate the connected process requiring
heated water (faucet, shower, etc.), then
flush the system for 5 minutes to ensure all
air is purged from the system.
NOTICE! Failure to bleed air properly
will damage elements and
cause heater malfunction.
Be sure that plumbing and electrical are complete per Start Up Check List.
WARNING Make sure the breaker for the heater is OFF.
H
When startup is complete, leave the two
or three pole switch or circuit breaker
in the ON position. The digital display
should read ambient temperature and
OFF.
GTurn on the connected process; observe
output temperature rise to setpoint.
On NEMA 1 controller, set point and
output temperatures are located side
by side. On the NEMA 4/4X controller,
the top portion of temperature controller
displays output temperature, bottom
displays setpoint temperature.
E
If your heater has the N4-EXP2 or N4X-
EXP2 option and is located in a Class
I Division 2 area, please review Special
Instructions & Operation Instructions
section for all proper electrical
connections and sealing to ensure
the installation will provide the proper
protection. Proceed to Step F once you
have completed the steps in the Special
Instructions & Operation Instructions or if you
do not have this option.

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HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
NEMA 1 Digital Controller Operation
6
Keys and Displays Function
Setpoint Up and Down Buttons In the Home Page, adjusts the set point in the right display. In other
pages, changes the upper display to a higher or lower value, or changes a
parameter selection.
Infinity Key ∞Back to Home page
Advance Key Advances through parameter prompts
Output Indicators (1-5) Number lights indicate activity of outputs 1 through 5. A flashing light
indicates retransmit activity.
Setpoint Temperature
(Right Side Display)
Displays:
• Setpoint
• Percent Power
• Temperature units °F or °C
• Menu prompt name
• Alarm code
Output Temperature
(Left Side Display)
Displays:
• Actual process temp. of outgoing water
• Prompt parameter value
• Error code
Output
Temp. Output
Indicators
Setpoint
Temp.
Infinity
Key Advance
Key
Setpoint
Up
Setpoint
Down
Output
Temp.
Setpoint
Temp. Output
Temp.
No Flow
The pre-programmed digital controller is mounted through the bezel on the enclosure door/cover. The
digital controller will be powered but the display will read OFF until water is flowing through the heater. The
display will then display the setpoint temperature (See appropriate Digital Controller Operation section for
more information).
Layout Diagram ON - Heating OFF - No Flow

11
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
NEMA 4/4X Digital Controller Operation
7
Keys and Displays Upper Display Lower Display Function
Setpoint Up Button Increases output temperature
Setpoint Down Button Decreases output temperature
Infinity Key Back to Home page
Advance Key Advances through output parameters
Output Indicators (1-5) Output 1,2,3,4 or 5 are active and operating if
these LEDs are illuminated.
Setpoint Temperature
(Lower Display)
Displays:
• Setpoint
• Percent Power
• Temperature units F or C
• Menu prompt name
• Alarm code
Output Temperature
(Upper Display)
Displays:
• Actual process temp. of outgoing water
• Prompt parameter value
• Error code
Output Indicators
Output Temp.
Output
Temp. Output
Temp.
No Flow
Setpoint
Temp.
Setpoint Temp.
Setpoint Up
Setpoint Down
Advance KeyInfinity Key
EZ Key
Layout Diagram ON - Heating OFF - No Flow
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5

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HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Perform Operational Test No. 1
Perform Operational Test No. 2
7
8
BStart the water flow through the heater by
starting the process or fixture this heater is
connected to in order to activate heater.
ATurn on hot water faucet/fixture/process. The
heater should activate immediately.
D
Press the up or down arrow keys to
adjust the set temperature. The controller
displays the temperature of water
measured at the outlet.
BTurn off hot water faucet/fixture/process.
The flow switch will deactivate and shut
off power to the heater.
E
Test water temperature and stability at
outlet by viewing the display. Controller
displays (in red) the temperature of water
exiting the heater.
C
When flow rate reaches approximately
0.5gpm, the flow switch recognizes this
condition and begins the heating process.
When the flow switch activates:
• The display changes from OFF to the output
temperature, verifying power supply connection
to the heating elements via the triac switches.
• Element load lights may be solid or flash
in unison as heating elements modulate
depending on the hot water demand.
• Digital temperature controller shows water
temperature. Additional programming is
not necessary.
Heater will not energize heating elements if the
inlet water temperature is equal to or greater than
the temperature set on the digital controller .
If the water flow exceeds maximum heating capacity of the heater, the temperature of water at the outlet
may be lower than the temperature selected on the controller. See table below to determine maximum
temperature rise capabilities.
Each model has precise specifications for temperature rise capabilities.
Temperature Rise (GPM & F°)
Models 208V, 240V, 277V, 480V kW 1 gpm
ΔT °F
1.5 gpm
ΔT °F
2 gpm
ΔT °F
2.5 gpm
ΔT °F
3 gpm
ΔT °F
3.5 gpm
ΔT °F
4 gpm
ΔT °F
HL05 5 34 23 17
HL06 6 41 27 20
HL10 10 68 45 34 27 23 20 17
HL12 12 82 55 41 33 27 23 20
HL15 15 102 68 51 41 34 29 26
HL18 18 122 82 61 49 41 35 31
Temperature Rise (lpm & C°)
Models 208V, 240V, 277V, 480V kW 3.8 lpm
ΔT °C
5.7 lpm
ΔT °C
7.6 lpm
ΔT °C
9.5 lpm
ΔT °C
11.4 lpm
ΔT °C
13.3 lpm
ΔT °C
15.1 lpm
ΔT °C
HL05 5 19 13 9
HL06 6 23 15 11
HL10 10 38 25 19 15 13 11 9
HL12 12 46 31 23 18 15 13 11
HL15 15 57 38 28 23 19 16 14
HL18 18 68 46 34 27 23 19 17
WARNING Ensure the cover is on or enclosure door is closed prior to performing this operational test.
ASet the 2 or 3 pole switch or circuit breaker to
the ON position.

13
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Output heating capacity is reduced on the 480V units if these heaters are installed on 415V or 380V single or three
phase.
Contact the factory to supply this information.
Satisfactory performance of the heater is dependent upon a specific flow rate vs temperature rise capability. If the
desired temperature is not achieved, please verify the following:
1. Circuit breaker is on and rated for the maximum power draw.
2. Heater is drawing the proper current for the supply voltage on all the single phase or all the three phases.
3. All phase indicator lights are lit (not flashing) indicating maximum power draw and maximum
amperage is being drawn.
4. Flow rate and temperature rise in the water heating process are compatible with the heater specifications.
5. Verify there is no additional supply of cold water entering the line downstream of the heater.
Product Options
T190 High Temperature Option: Reach and maintain temperatures as high as 190°F.
IC Temperature Lock Out: Temperature lock out at specific °F or °C.
Low Flow (L25 & L15): Options include 0.25 GPM and .015 GPM for heating water at a lower flow as required.
D1 Control Interface: Provides 4–20ma communication interface with temperature controller.
TE2 Corrosive Fluid Protection: The TE2 option is a single layer of Xylan Fluoropolymeric coated heat exchanger
with bright annealed stainless steel elements, FDA Approved for Food Contact (use in deionized water applications).
N4-EXP2 & N4X-EXP2 (Explosion Proof Purge System): Keltech's EXP2 option makes heaters compliant for
classified areas; Class I Division 2, Groups A, B, C, D, Temp Code: T5. The Purge System requires a supply of clean
instrument air or inert gas (provided by installer). This supply maintains a positive internal pressure and prevents the
enclosure from filling with flammable gasses, dusts or vapors from the ambient environment. Complete installation
provided in this manual.
N4X (NEMA 4X Enclosure): The optional NEMA 4X corrosion resistant enclosure is designed for harsher
environments and made from 16 gauge 304 stainless steel. The NEMA 4X enclosure can also be specified with 316
stainless steel.
N4 (NEMA 4 Enclosure): The optional 18 gauge, NEMA 4 enclosure with ANSI61 gray, corrosion resistant paint.

14
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Maintenance
Preventative maintenance is important for optimal performance of the heater. To ensure the heater works properly,
always keep the inside of the enclosure dry. Moisture inside an enclosure increases the humidity, which condenses
on cooler surfaces. This can cause electrical problems and reduce the efficiency of enclosure insulation. To prevent
problems perform the following:
• Verify the interior of the enclosure is dry.
• Verify there are no leaks in seals of enclosure and that in high humidity environments all enclosure egresses are
properly sealed.
• Ensure plugs are in place on back side of enclosure.
• Check seals monthly during temperatures above 32°F (0°C) and weekly during temperatures below 32°F(0°C).
• Bimetal manual resets are set to trip at 175°F(79°C). If this temperature is reached, the bimetal manual reset
safeties will trip and need to be reset.
• All heaters require filtration of 150 microns or smaller to ensure proper operation. Y-strainers or additional filtration
should be verified and cleaned at least every 6 months or more often in areas where hard water sediment is
present in the water.
To clean the Y-Strainer:
1. Turn the power off at the circuit breaker panel.
2. Shut off the installer supplied cold water isolation valve to the heater.
3. Relieve pressure in the plumbing lines.
4. Position a bucket under the cold water inlet to catch any water that may still be in the pipe.
5. Loosen the plumbing connection on the Y-strainer to get to the screen.
6. Remove screen and clean out debris. Use a wire brush to clean smaller particles from the screen.
7. Once the screen is clean, put it back into the Y-strainer housing and secure the plumbing connection.
8. Before switching the power back on, bleed the air out of the lines by turning heater water supply back on and
the plumbing fixture or process farthest from the heater.
9. With the air purged, turn on all circuit breakers supplying the water heater.
• At the same time the Y-strainer or additional filtration is cleaned, it is a good practice to also check all valves
connected to the system. With no water flow through the heater, work both the inlet ball valves and the outlet gate
valves open and shut to break up any calcium deposits that may have formed from the valve being open for an
extended period of time. Power to the heater does not need to be turned off to do this.

15
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Troubleshooting for Controller
Problem Solution
No Power Verify power is on.
Turn power off. Check continuity of all internal fuses in
control transformer, heating elements or optional Fused
Disconnect circuits.
Check all field service circuit breakers or fuses.
Check system temperature limit control to make sure
it has not activated due to excessive heat exchanger
temperature or faulty sensor.
Turn power off. Check for loose or disconnected wires.
Check the incoming service connection. Voltage must
match name plate rated voltage. Labels are located on the
upper left of back plate (Serial Number Label).
Alarms do not occur. Make sure alarm set points are correct.
Make sure alarm is not latched.
Make sure alarm side settings are correct.
Make sure alarm type settings are correct.
Make sure alarm controller is not in diagnostic mode.
Alarms do not clear. Check power limit setting.
Check operation mode.
Check alarm output function.
Check temperature setting.

16
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Basic Troubleshooting
Problem Solution
The heater does not work or works intermittently. Flow switch works properly.
At the wires from the flow switch, ohm meter should read
Open without flow and Closed with flow.
Water flow through the heater is adequate to activate the
flow switch at 0.5 gpm or at the low flow options of 0.15 or
0.25 gpm.
Heater is wired with the proper breaker and wire size.
Refer to Electrical Specifications for Heater table in
section 3 for proper requirements.
Unit is receiving voltage from all 3 phases of the power
source. A load voltage reading is also helpful.
If the above steps do not solve the problem, some additional checks may be performed. Follow the
schematic to perform the following continuity checks:
High temperature bimetals (Manual Reset Safeties).
Optional ground fault breaker must be in the closed position for the unit to work.
All internal breakers must be in the ON position for the unit to work.
For additional information on Troubleshooting or other information, please call Keltech Inc. technical support at
1-800-999-4320. Please have Model No. and Serial No. available when seeking technical assistance. Serial No.
tag is located in the enclosure on the upper left hand corner of the back plate. Please record and maintain this
information at all times:
HL- Model No.
Serial No.
Turn power OFF before recording any Ohm readings.

17
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
Special Installation and Operating Instructions
Tankless Water Heaters With Optional Class I Division 2 Purge EXP2 Option
General Information
All Keltech Tankless Water Heaters with a model number suffix of – EXP2 have been fitted with a Z purge system to
pressurize the enclosure suitable for use in Class I Division 2 Hazardous Locations.
A Continuous Flow (Model CF) Mini-Z Pressurizing System has been fitted to the side of the enclosure.
Outlet
18"
(458mm)
Max
Explosion proof
sealing fitting
supplied by others
Conduit Hub
Class 1 Div. 2
supplied by others
1
1
2
3
4
5
24
5
Suggested region for power
entrance at right/bottom of
enclosure. Entrance hole and
components to be provided by
installer.
Purge Control Panel
Class 1 Division 2
All installation egress from
panel must be sealed (electrical
conduit) for proper explosion proof
installation.
Spark arrestor with calibration
orifice is located in the bottom of the
enclosure.
Purge gas/compressed air inlet
fitting is located behind the purge
control unit and through bottom of
enclosure.
EXP2 Installation Notes
1. Any tubing, conduit or fittings connected to the Pressurized Enclosure (PE) must conform to local codes for
flammability ratings.
2. All egress into PE must be plugged and properly sealed to minimize leakage of purge air. Use hazardous
location sealing fittings suitable for Class I locations within 18" of enclosure.
3. The EXP2 purge system option is a continuous flow purge system mounted inside the cabinet enclosure and
calibrated to flow at 0.9 SCFM. To minimize waste, plug and seal all openings and conduit.
4. The system is designed for use primarily with compressed air. The source of the compressed air must be
from a non-classified area (see Purge Gas Supply Notes). Purge air must be clean, dry and free of flammable
gases. When inert compressed gases are used (Nitrogen, for example) the installer and facility manager must
take suitable precautions on-site so that buildup of the inert gas does not present a health hazard. Where risk
of asphyxiation exists, a warning label must be fitted to the Pressurized Enclosure (PE).
5. Adjustment of Purge System is not necessary. System is fully calibrated.
6. Connect to Purge System where indicated above. Connection port is 1/4" NPT female. Supply pressure must be
regulated to 60–115 PSI.
Inlet
Explosion proof (EXP2) option is only available
on NEMA 4 or NEMA 4X Enclosure.

18
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Purge Gas Supply Notes
An alarm shall be provided to indicate failure of the protective gas supply to maintain the required pressure. Piping for
the protective gas shall be protected against mechanical damage.
Where the compressor intake line passes through a classified location, it shall be constructed of noncombustible
material, designed to prevent leakage of flammable gases, vapors, or dusts into the protective gas, and protected
against mechanical damage and corrosion.
The electrical power for the protective gas supply (blower, compressor, etc.) shall be supplied either from a separate
power source or from the protected enclosure power supply prior to any service disconnects of the protected
enclosure. Any protected enclosure that can be isolated from the protective gas supply shall be equipped with an
alarm. Where an alarm is used to indicate the loss of pressure in the cabinet:
• The alarm shall be located at a constantly attended location.
• The alarm actuator shall take its signal from the protected enclosure and shall not be installed between the
enclosure and the protective gas supply.
• The alarm actuator shall be mechanical, pneumatic, or electrical.
• Electrical alarms and electrical alarm actuators shall be approved for the location in which they are installed.
• No valves shall be permitted between the alarm actuator and the enclosure.
Intrinsically Safe (IS) Installation
1. Electrical equipment connected to associated apparatus should not use or generate more than 250 volts.
2. Installation shall be in accordance with the manufacturer's instructions and the National Electrical Code (NFPA 70).
3. For guidance on Installation see ANSI/ISA RP12.6 (Installation of IS Instrument System in Class I
Hazardous Locations).
4. Voc or Vt of associated apparatus is less than Vmax
Isc or IT of associated apparatus is less than Imax
Ci plus capacitance of interconnecting cabling is less than Ca of the associated apparatus
Li plus inductance of interconnecting cabling is less than La fo the associated apparatus
5. "Simple Apparatus" is a device that will not generate or store more than 1.2V, 0,1A, 25mW or 20uJ
Hazardous Location
Class I , Division 2
Groups A, B, C, D
T5 Hazardous (classified) Areas
MiniPurge: Option Code /IS
Vmax = 30v
Imax = 350mA
Ci = 0 Li = 0
Non- Hazardous Location
(or suitably protected enclosure)
Power Supply
Outputs to relays or
power contactors
Intrinsically Safe
Interface Unit
Simple apparatus
device

19
Installation HL-Series Tankless Heater
Keltech • 215-1823 Rev. A; ECN 150023 11/24/2015
IS Installation continued…
All quarter turn latches in the door of the PE must be fully latched for proper operation. Power to the PE must be
turned off before opening the enclosure.
WARNING This Pressurized Enclosure shall not be opened unless the area is known to be free of
flammable materials or unless all devices within have been de-energized.
Power shall not be restored after the enclosure has been opened until the enclosure has been purged for allotted
time (See table below). Time begins when pressure indicator turns green after the door of the enclosure has been
closed and fully latched.
WARNING Ignition of potentially explosive gas/air mixtures may result if power is turned on before the
allotted purge time!
Expo Technologies CF systems have a Minimum Pressure Sensor set to a pressure of at lease 0.1" WC (0.25bars). When
the PE pressure is above this set point the sensor produces a positive Pressurized signal. This is displayed on the Red/
Green indicator located on the Purge System. This signal can be used to operate an electrical contact for a remote Alarm.
This signal may be supplied to the pressure operated switch suitable for Intrinsically Safe circuit in accordance. When the
enclosure pressure falls below the set point of the sensor, the Pressurized signal is removed, and the Alarm conditions
occurs. This Alarm must be located where it can be readily observed according to NFPA496 requirements. No valves may
be fitted between the Expo Technologies system and the alarm switch.
WARNING Never turn on the power without purging first, unless you have proved the interior of the PE is gas
free and checked that the “Pressurized” indicator is green!
Commissioning Test
Commissioning Continuous Flow Purge Keltech Option EXP2 System:
1. Open the air or gas supply shutoff valve.
2. Adjust the Flow Control Valve (FCV) so that the enclosure pressure rises to the point where the "Pressurized"
indicator turns green.
3. Lower the PE pressure until the Pressurized indicator turns Red.
4. Open the FCV again and set the PE pressure to a level somewhere between the Minimum Pressure
Sensorset point and the RLV opening pressures. This working pressure is not critical. Enough pressure to keep
the“Pressurized” indicator Green is sufficient.
5. On EXP2 Purge System the timing function if performed by the user. The user must ensure that the time delay
between the indicator turning Yellow and the application of power to the PE is not less than the minimum time
required to purge the PE as shown in the table below.
Normal Operation: Turn the air supply valve ON to start or OFF to stop the system. The user must close the Power
Switch only after the enclosure has been pressurized and purged sufficiently to ensure that the interior of the enclosure
is gas free. It is the operator’s responsibility to shut off the power as soon as possible after a pressure failure.
PURGE TIME CHART - EXP2 Option
for use with EXPO Mini Z Purge 1ZCF/bp/IS
Model/Enclosure
Group Size
Cubic
Feet
Volume
Exchanges
X 4
Orifice
Size
Orifice
No.
Purge
Time
(Minutes)
HL 5-18kW (N4) 1.56 6.23 0.4 #1 16
HL 5-18kW (N4X) 2 8 0.4 #1 20

20
HL-Series Tankless Heater Installation
11/24/2015 Keltech • 215-1823 Rev. A; ECN 150023
Special Installation Maintenance
Routine Maintenance of the System (Every 6 months)
Recommended maintenance of the systems is as follows:
Repeat Commissioning test at least every six months. The test includes checking the opening pressure of the Relief
Valve, setting of the Minimum Pressure Sensor, the “Normal Working Pressure” of the enclosure. Test that the interlock
and alarms function correctly.
Check the Relief Valve and any other Spark Arrestors. Remove any debris or corrosion, or replace the Spark Arrestor.
Check the condition of the air supply filter element. Clean or replace it as necessary.
Periodic Maintenance (Every 18-24 months)
At least every two years, the following additional checks are recommended:
Apparatus (Heater, Purge Systems, Alarms etc.) is suitable for the Hazardous Location.
There are not unauthorized modifications.
The source of air is uncontaminated.
The interlock and alarms function correctly.
Approval labels are legible and undamaged.
Adequate spare parts are carried.
The action of pressure failure is correct.