Heat-Flo SSL-10 User manual

COMMERCIAL ELECTRIC WATER HEATERS
INSTRUCTION MANUAL
MODELS SSL-10/ 20/ 30/ 40/ 50 LOW BOY UNITS
MODELS SSN-40/ 52/ 66/ 80/ 119 TALL UNITS
INSTALLATION | OPERATION | SERVICE |
MAINTENANCE | LIMITED WARRANTY
Conforms to UL1453
for Electric Commercial
Water Heaters.
Certied to CAN/ CSA
STD C22.2 No. 110-94
Heat-Flo, Inc. | www.heat-o.com | Uxbridge, MA 01569
WARNING
Read and understand this instruction
manual and the safety messages herein
before installing, operating, or servicing
this water heater.
Failure to follow these instructions and
safety messages could result in death
or serious injury.
This manual must remain with the water
heater.
WARNING
If the water heater becomes immersed
in water up to or above the level of the
bottom of the element doors, the heater
should be examined by a qualied
service agency before it is placed in
operation. See Page 2.
PLACE INSTRUCTIONS ADJACENT TO WATER HEATER & NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
80-257 REV B_20190409

1
SAFE INSTALLATION, USE, AND SERVICE
The proper installation, use, and servicing of this water heater is extremely important to your safety and the safety of others.
Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn
you and others of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual.
It is very important that the meaning of each safety message is understood by you and others who install, use, or service
this water heater.
DANGER
WARNING
CAUTION
CAUTION
This is the safety alert symbol. It is used to alert you to
potential personal injury hazards. Obey all safety messages
that follow this symbol to avoid possible injury or death.
DANGER indicates an imminently hazardous situation,
which (if not avoided) could result in death or injury.
WARNING indicates a potentially hazardous situation,
which (if not avoided) could result in death or injury.
CAUTION indicates a potentially hazardous situation, which
(if not avoided) could result in minor or moderate injury.
CAUTION used without the safety alert symbol indicates a
potentially hazardous situation, which (if not avoided) could
result in property damage.
All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety
message, and how to avoid the risk of injury.
IMPORTANT DEFINITIONS
Qualied Installer or Service Agency:
Installation and service of this water heater requires ability equivalent to that of a Qualied Agency (as dened by ANSI
below) in the eld involved. Installation skills such as plumbing and electrical are required in addition to electrical testing
skills when performing service.
ANSI Z223.1 2006 Sec. 3.3.83:
Qualied Agency: “Any individual, rm, corporation, or company that either in person or through a representative is
engaged in and is responsible for (a) the installation, testing, or replacement of gas piping or (b) the connection,
installation, testing, repair, or servicing of appliances and equipment; that is experienced in such work; that is familiar
with all precautions required; and that has complied with all the requirements of the authority having jurisdiction.”

2
GENERAL SAFETY INFORMATION
PRECAUTIONS
DO NOT USE THIS WATER HEATER IF ANY PART HAS
BEEN EXPOSED TO FLOODING OR WATER DAMAGE.
Immediately, call a qualied service technician to inspect the
water heater and to replace any part of the control system
that has been under water.
If the unit is exposed to the following, do not operate heater
until all corrective steps have been made by a qualied
service technician.
1. External Fire
2. Damage
3. Firing Without Water
GROUNDING INSTRUCTIONS
This water heater must be grounded in accordance with
National Electrical Code and/ or local codes. These must
be followed in all cases. Failure to ground this water heater
properly may also cause erratic control system operation on
ELECTRONIC CONTROL models.
This water heater must be connected to a grounded metal,
permanent wiring system, or an equipment grounding
conductor must be run with the circuit conductors and
connected to the equipment grounding terminal or lead on
the water heater.
HYDROGEN GAS (FLAMMABLE)
Hydrogen gas can be produced in a hot water system
served by this heater that has not been used for a long
period of time (generally two weeks or more). Hydrogen gas
is extremely ammable. To reduce the risk of injury under
these conditions, it is recommended that the hot water faucet
be opened for several minutes at the kitchen sink before
using any electrical appliance connected to the hot water
system. If hydrogen is present, there will probably be an
unusual sound, such as air escaping through the pipe as the
water begins to ow THERE SHOULD BE NO SMOKING
OR OPEN FLAME NEAR THE FAUCET AT THE TIME IT IS
OPEN.
WARNING
EXPLOSION HAZARD
Flammable hydrogen gases
may be present.
Keep all ignition sources
away from faucet when
turning on hot water.
When servicing this unit, verify the power to the unit is turned off prior to opening the control cabinet door.
WARNING
EXPLOSION HAZARD
Overheated water can cause water
tank explosion.
Properly sized temperature and
pressure relief valve must be
installed in opening provided.
WARNING
Read and understand this
instruction manual and the safety
messages herein before installing,
operating, or servicing this water
heater.
Failure to follow these instructions
and safety messages could result
in death or serious injury.
This manual must remain with the
heater.
WARNING
Before removing any access panels
or servicing the water heater, make
sure the electrical supply to the
water is turned OFF.
Failure to do this could result in
death, serious bodily injury, or
property damage.
DANGER
Water temperature over 125˚F can
cause severe burns, resulting in
severe injury or death.
Children, the elderly, and physically
or mentally disabled are at highest
risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting valves are
available.
Read instruction manual for safe
temperature setting.
CAUTION
IMPROPER INSTALLATION, USE, AND SERVICE
MAY RESULT IN PROPERTY DAMAGE
Do not operate water heater if any part has been exposed to
ooding or water damage.
Inspect anode rods regularly; replace when signicantly depleted.
Install in location with adequate drainage.
Fill tank with water before operation.
Properly sized thermal expansion tanks are required on all closed
water systems.
Refer to this manual for installation
and service instructions.

3
TABLE OF CONTENTS
INTRODUCTION
Thank You for purchasing this water heater. Properly
installed and maintained, it should give you years of trouble-
free service.
Abbreviations found in this instruction manual include:
ANSI - American National Standards Institute
AHRI - Air Conditioning, Heating, and Refrigeration
Institute.
NEC - National Electrical Code
NFPS - National Fire Protection Association
UL - Underwriter’s Laboratory
PREPARING FOR THE INSTALLATION
1. Read the “General Safety Information” section of this
manual rst, then read the rest of the manual carefully.
If you don’t follow the safety rules, the water heater may
not operate safely. It could cause DEATH, SERIOUS
BODILY INJURY, AND/OR PROPERTY DAMAGE.
This manual contains instructions for the installation,
operation, and maintenance of the electric water heater.
It also contains warnings throughout that must be read
and understood. All warnings and all instructions are
essential to the proper operation of the water heater and
your safety. READ THE ENTIRE MANUAL BEFORE
ATTEMPTING TO INSTALL OR OPERATE THE WATER
HEATER.
Be sure to turn off all power when working on or
near the electrical system of the heater. Never touch
electrical components with wet hands or when
standing in water.
When replacing fuses, always use the correct size for the
circuit.
The model and rating plates on page 5 interprets
certain markings into useful information. Both of these
references should be used to identify the heater, its
components, and optional equipment.
2. The installation must conform with these instructions
and the local code authority having jurisdiction and the
requirements of the power company. In the absence of
local codes, the installation must comply with the latest
editions of the National Electrical Code, NFPA 70 or the
Canadian Electrical Code CSA C22.1. The National
Electrical Code may be ordered from :
National Fire Protection Association
1 Batterymarch Park
Quincy, MA 02269
The Canadian Electrical Code is available from:
Canadian Standards Association
8501 East Pleasant Valley Rd.
Cleveland OH, 44131
3. If after reading this manual you have any questions or do
not understand any portion of the instructions, call the
toll free number listed on the back cover of this manual
for technical assistance.
A sample rating plate is shown on page 5. In order to
expedite your request, please have full model and serial
number available for the technician.
4. Carefully plan your intended placement of the water
heater. Examine the location to ensure the water heater
complies with the “Locating the Water Heater” section of
this manual.
Installation and service of this water heater requires
ability equivalent to that of a licensed tradesman or
qualied agency (page 2) in the eld involved. Plumbing
and electrical work are required.
WARNING
Before removing any access panels
or servicing the water heater, make
sure the electrical supply to the
water is turned OFF.
Failure to do this could result in
death, serious bodily injury, or
property damage.
SAFETY INFORMATION --------------------------------------------------------------- 1 - 2
INTRODUCTION ---------------------------------------------------------------------- 3
DIMENSIONS & CAPACITIES DATA -------------------------------------------------------- 4
APPROVALS ------------------------------------------------------------------------- 5
MODEL AND RATING ------------------------------------------------------------------- 5
FEATURES & COMPONENTS------------------------------------------------------------- 6
LOCATING THE WATER HEATER ---------------------------------------------------------- 7
INSTALLATION---------------------------------------------------------------------- 7 - 9
ELECTRICAL ---------------------------------------------------------------------- 9 - 11
WIRING DIAGRAMS------------------------------------------------------------------- 10
OPERATION ------------------------------------------------------------------------ 12
TEMPERATURE REGULATION ----------------------------------------------------------- 13
MAINTENANCE ---------------------------------------------------------------------- 14
TROUBLESHOOTING- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 14 - 15
LEAKAGE CHECKPOINTS -------------------------------------------------------------- 15
REPLACEMENT PARTS ------------------------------------------------------------- 15 - 16
LIMITED WARRANTY ------------------------------------------------------------------ 17

4
DIMENSIONS AND CAPACITIES DATA
Model Number Gallon
Capacity
Maximum KW
Input
No. of
Elements Height to Top Diameter Weight
Compact Models - Single Elements
SSL-10S 10 6.1 1 18.0 19.0 30
SSL-20S 20 6.1 1 24.5 23.5 35
Lowboy models - Double Elements
SSL-30D 30 12.2 2 34.0 23.5 75
SSL-40D 40 12.2 2 36.0 28.0 90
SSL-50D 50 12.2 2 40.0 28.0 105
Tall Models - Double Elements
SSN-40D 40 12.2 2 44.0 23.5 90
SSN-52D 50 12.2 2 54.0 23.5 105
SSN-66D 66 12.2 2 48.0 28.0 140
SSN-80D 80 12.2 2 56.0 28.0 140
SSN-119D 119 12.2 2 74.0 28.0 175
RECOVERY CAPACITIES
Element Wattage
(Upper/ Lower)
KW
Input
U.S. Gallons/ Hr. at Temperature Rise Indicated
36°F 40°F 54°F 60°F 72°F 80°F 90°F 100°F 108°F 120°F 126°F
Non-Simultaneous Operation
/1500 1.5 17 15 11 10 8 8 7 6 6 5 5
/2000 2.0 23 20 15 14 11 10 9 8 8 7 6
/2500 2.5 28 25 19 17 14 13 11 10 9 8 8
3000/3000 3.0 34 30 23 20 17 15 14 12 11 10 10
4000/4000 4.0 45 41 30 27 23 20 18 16 15 14 13
4500/4500 4.5 51 46 34 30 25 23 20 18 17 15 14
5000/5000 5.0 56 51 38 34 28 25 23 20 19 17 16
6000/6000 6.0 68 61 45 41 34 30 27 24 23 20 19
Simultaneous Operation
3000/3000 6.0 68 61 45 41 34 30 27 24 23 20 19
4000/4000 8.0 90 81 60 54 45 41 36 32 30 27 26
4500/4500 9.0 101 91 68 61 51 46 41 36 34 30 29
5000/5000 10.0 113 101 75 67 56 51 45 41 37 34 32
6000/6000 12.0 135 122 90 81 67 61 54 49 45 41 39
DIMENSIONS & CAPACITIESRECOVERY CAPACITIES
ALL HOT OUTLETS AND COLD INLETS SUPPLIED WITH WATTS 3/4
LF301 DIELECTRIC UNION WITH 4” COPPER TUBE.

5
APPROVALS
MODEL AND RATING
COMMERCIAL ELECTRIC
STORAGE TANK WATER HEATER
HEAT-FLO, INC.
UXBRIDGE, MA USA
MODEL NUMBER SERIAL NUMBER
VOLTS - AC PHASE
WAT TS
UPPER
WAT TS
LOWER
CIRCUIT
INTERLOCK
1 PH/ 3 PH 1 PH 3 PH
RATED
CAPACITY
WORKING
PRESSURE
(MAX PSI)
%WAT TS
TOTAL WATTS CONNECTED STANDBY LOSS
Conforms to UL 1453
Cered to CAN/CSA
STD C22.2 No. 110-94
MASS Approval #P1-0119-315
SSL-10/ 20/ 30/ 40/ 50 & SSN-40/ 50/ 60/ 80/ 119
Conforms to UL1453
for Electric Commercial
Water Heaters.
Certied to CAN/ CSA
STD C22.2 No. 110-94

6
FEATURES AND COMPONENTS
ELECTRONIC CONTROL MODELS: Typical Water Heater Installations by Model Designation.
COLD WATER INLET
SHUTOFF VALVE
WATTS 3/4 LF301
DIELECTRIC UNION W/ 4” CU TUBE
(SUPPLIED W/ UNIT)
1 7/16” M THREADED CONNECTION
DRAIN VALVE
T&P VALVE MUST BE PIPED A
MAX. OF 6” FROM FLOOR DRAIN
HOT WATER SUPPLY
T&P VALVE
WATTS 3/4 LF301
DIELECTRIC UNION W/ 4” CU TUBE
(SUPPLIED W/ UNIT)
1 7/16” M THREADED CONNECTION
FUSED ELECTRICAL SUPPLY SWITCH
ELECTRICAL JUNCTION BOX
ACCESS PANEL
DRAIN VALVE
T&P VALVE MUST BE PIPED A
MAX. OF 6” FROM FLOOR DRAIN
SHUTOFF VALVE
WATTS LF301 DIELECTRIC
UNION W/ 4” CU TUBE
(SUPPLIED W/ UNIT)
COLD WATER INLET
HOT WATER SUPPLY
ACCESS PANEL
T&P VALVE
WATTS 3/4 LF301 DIELECTRIC
UNION W/ 4” CU TUBE
(SUPPLIED W/ UNIT)
INSTALL VACUUM RELIEF IN COLD
WATER INLET LINE AS REQUIRED
BY LOCAL CODES.
INSTALL THERMAL EXPANSION TANK IF
CHECK VALVE OR PRESSURE-REDUCING
VALVE IS USED IN SUPPLY LINE.
INSTALL SUITABLE DRAIN PANS UNDER WATER HEATERS TO
PREVENT DAMAGE DUE TO LEAKAGE. REFER TO WATER
HEATER LOCATION ON PAGE 7.
SSN/SSL DUAL-ELEMENT MODELS
SSN/SSL SINGLE-ELEMENT MODELS
1 7/16” M THREADED CONNECTION
1 7/16” M THREADED CONNECTION
ELECTRICAL CONNECTION

7
LOCATING THE WATER HEATER
FACTS TO CONSIDER ABOUT THE LOCATION
The water heater should be located as close as possible
to/or centralized to the water piping system. The water
heater should be located in an area not subject to freezing
temperatures.
The water heater should be located in an area where
leakage of the tank or connections will not result in damage
to the area adjacent to the heater or to lower oors of the
structure.
Such pans should be at least two inches deep, have a
minimum length and width of at least two inches greater
than the diameter of the heater and should be piped to an
adequate drain.
Water heater life depends upon water quality, water
pressure, and the environment in which the water heater
is installed. Water heaters are sometimes installed in
locations where leakage may result in property damage,
even with the use of a drain pan piped to a drain; however,
unanticipated damage can be reduced or prevented by a
leak detector or water shut-off device used in conjunction
with a piped drain pan. These devices are available from
some plumbing supply wholesalers and retailers, and
detect and react to leakage in various ways:
Sensors mounted in the drain pan that trigger an alarm
or turn off the incoming water to the water heater when
leakage is detected.
Sensors mounted in the drain pan that turn off the water
supply to the entire home when water is detected in the
drain pan.
Water supply shut-off devices that activate based on the
water pressure differential between the cold water and
hot water pipes connected to the water heater.
Devices that will turn off the gas supply to a gas water
heater while at the same time shutting off its water
supply.
CLEARANCES
A minimum clearance of 4” must be allowed for access to
replaceable parts such as thermostats, drain valve, and
relief valve.
Adequate clearance for servicing this water heater should
be considered before installation, such as changing the
anodes, etc...
CAUTION
PROPERTY DAMAGE HAZARD
All water heaters eventually leak.
Do not install without adequate drainage.
INSTALLATION
REQUIRED ABILITY
Installation and service of this water heater requires ability
equivalent to that of a qualied installer or service agency
(page 2) in the eld involved. Plumbing and electrical
work is required.
GENERAL
The installation must conform with these instructions
and the local code authority having jurisdiction and the
requirements of the power company. In the absence of
local codes, the installation must comply with the latest
editions of the National Electrical Code, NFPA 70 or the
Canadian Electrical Code CSA C22.1. The National
Electrical Code may be ordered from:
National Fire Protection Association
1 Batterymarch Park,
Quincy, MA 02269
The Canadian Electrical Code is available from:
Canadian Standards Association
8501 East Pleasant Valley Rd.
Cleveland OH, 44131
DO NOT test electrical system before heater is lled with
water. Follow the START UP procedure in the OPERATION
section of this manual.
The principle components of the heater are identied in
the Features and Components illustration on page 6.
MIXING VALVE USAGE:
Water heaters are intended to produce hot water. Water
heated to a temperature which will satisfy space heating,
clothes-washing, dish-washing, cleaning, and other
sanitizing needs can scald and permanently injure you upon
contact. Some people are more likely to be permanently
DANGER
Water temperature over 125˚F can
cause severe burns, resulting in
severe injury or death.
Children, the elderly, and physically
or mentally disabled are at highest
risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting valves are
available.
Read instruction manual for safe
temperature setting.

8
injured by hot water than others. These include the
elderly, children, the inrm, or physically/ developmentally
disabled. If anyone using hot water in you home ts into
one of these groups, or if there is a local code or state law
requiring a maximum water temperature at the hot water
tap, then you must take special precautions. In addition to
using the lowest possible temperature setting that satises
your hot water needs, a means such as a MIXING VALVE
should be used at the hot water taps used by these people
or at the water heater.
MIXING VALVES for reducing point of use temperature
are available and are to be set at a maximum of 125˚F.
Consult a qualied installer or service agency. Follow all
manufacturer’s instructions for installation of these valves.
Before changing the factory setting on the thermostat,
read the Temperature Regulation section in this manual.
CONTAMINATED WATER
This water heater shall not be connected to any heating
system(s) used with a non-potable water heating appliance.
Toxic Chemicals, such as those used for boiler treatment,
shall not be introduced into this system.
CIRCULATING PUMP
Field installed circulating pumps should be of all bronze
construction.
INSULATION BLANKETS
Insulation blankets are available to the general public
for external use on electric water heaters but are not
necessary with this product. The purpose of an insulation
blanket is to reduce the standby heat-loss encountered
with storage tank heaters. Your water heater meets or
exceeds the EPACT and ASHRAE/ IES 90.1 standards
with respect to insulation and standby loss requirements,
making an insulation blanket unnecessary.
Should you choose to apply an insulation blanket to this
heater, you should follow these instructions below. Failure
to follow these instructions can result in re, serious
personal injury, or death.
Do not cover the Temperature and Pressure (T&P) Valve
with an insulation blanket.
Do not over the instruction manual. Keep it on the side
of the water heater or nearby for future reference.
Obtain new warning and instruction labels for placement
on the blanket directly over the existing labels.
TEMPERATURE AND PRESSURE RELIEF VALVE
This water heater is provided with a properly rated/ sized
and certied combination Temperature and Pressure
Relief Valve. The valve is certied by a nationally
recognized testing laboratory that maintains periodic
inspection of production of listed equipment of materials
as meeting the requirements for Relief Valves for Hot
Water Supply Systems, ANSI Z21.22 · CSA 4.4, and the
code requirements of ASME.
If replaced, the new valve must meet the requirements of
local codes, but not less than a combination Temperature
and Pressure Relief Valve rated/ sized and certified as
indicated in the above paragraph. The new valve must be
marked with a maximum set pressure not to exceed the
marked hydrostatic working pressure of the water heater
(150 psi = 1,035 kPa) and a discharge capacity not less
than the water heater BTU/ hr or KW input rate as shown
on the water heater’s model rating plate.
For safe operation of the water heater, the temperature
and pressure relief valve must not be removed from its
designated opening, nor plugged. The T&P Valve must
be installed directly into the fitting of the water heater
designated for the relief valve. Install the discharge piping
so that any discharge will exit only within 6 inches above,
or at any distance below, the structural floor. Be certain
that no contact is made with any live electrical part. The
use of more than four elbows can cause restriction and
reduce the discharge capacity of the valve.
No valve or other obstruction is to be placed between the
relief valve and the tank. Do not connect discharge piping
directly to the drain unless a 6-inch air gap is provided. To
prevent bodily injury, hazard to life, or property damage,
the relief valve must be allowed to discharge water in
adequate quantities should circumstances demand. If the
discharge pipe is not connected to a drain or other suitable
means, the water flow may cause property damage.
INSTALLATION CONTINUED
WARNING
TOXIC CHEMICAL HAZARD
Do not connect to non-potable water system.
WARNING
EXPLOSION HAZARD
Temperature and Pressure Relief
Valve must comply with ANSI
Z21.22 and ASME code.
Properly-sized Temperature and
Pressure Relief Valve must be
installed in opening provided.
Failure to install relief valve can
result in overheating and excessive
tank pressure.
Failure to follow these instructions
can cause serious injury or death.
INSTALLATION CONTINUED ON NEXT PAGE

9
GENERAL
The installation must conform with these instructions
and the local code authority having jurisdiction, and the
requirements of the power company. In the absence of
local codes, the installation must comply with the current
editions of the National Electrical Code, NFPA 70 or the
Canadian Electrical Code, CSA C22.1.
An electrical ground is required to reduce risk of electrical
shock or possible electrocution. The water heater should
be connected to a separate grounded branch circuit with
over-current protection and disconnect switch. The water
heater should be grounded in accordance with national
and local codes.
Voltage applied to the heater should not vary more
than +5% to -10% of the model rating plate marking for
INSTALLATION CONTINUED
The Discharge Pipe:
Shall not be smaller in size than the outlet pipe size of the
valve or have any reducing couplings or other restrictions.
Shall not be plugged or blocked.
Shall be of material listed for hot water distribution.
Shall be installed so as to allow complete drainage of both
the T&P Valve and the discharge pipe.
Must terminate at a maximum of 6 inches above a floor
drain or external to the building. In cold climates, it is
recommended that the discharge pipe be terminated at an
adequate drain inside the building.
Shall not have any valve or other obstruction between the
relief valve and the drain.
The T&P Valve must be manually operated at least once a
year. Caution should be taken to ensure that:
(1) no one is in front of or around the outlet of the T&P
Valve discharge line, and
(2) the water manually discharged can cause bodily
injury or property damage because the water may be
extremely hot.
If after manually operating the T&P Valve it fails to
completely reset and continues to release water,
immediately close the cold water inlet to the water heater,
follow the instructions in this manual, and replace the T&P
Valve with a properly rated/ sized new one.
If you do not understand these instructions or have any
questions regarding the T&P Valve, call the toll free
number listed on the back cover of this manual for technical
assistance.
CLOSED WATER SYSTEMS
Water supply systems may (because of code requirements
or such conditions as high line pressure, among others)
have installed devices such as pressure reducing valves,
check valves, and back flow preventers. Devices such as
these cause the water system to be a closed system.
THERMAL EXPANSION
As water is heated, it expands (thermal expansion). In a
closed system, the volume of water will grow when it is
heated. As the volume of the water grows, there will be a
corresponding increase in water pressure due to thermal
expansion. Thermal expansion can cause premature
tank failure (leakage). This type of failure is not covered
under the limited warranty. Thermal expansion can also
cause intermittent T&P Valve operation: water discharged
from the valve due to excessive pressure build-up. This
condition is not covered under the limited warranty. The
T&P Valve is not intended for the constant relief of thermal
expansion.
A properly-sized thermal expansion tank should be
installed on all closed systems to control the harmful
effects of thermal expansion. Contact a local plumbing
service agency to have a thermal expansion tank installed.
CAUTION
WATER DAMAGE HAZARD
Temperature and Pressure Relief Valve discharge
pipe must terminate to an adequate drain.
DANGER
Water temperature over 125˚F can
cause severe burns, resulting in
severe injury or death.
Children, the elderly, and physically
or mentally disabled are at highest
risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting valves are
available.
Read instruction manual for safe
temperature setting.
ELECTRICAL
WARNING
Before removing any access panels
or servicing the water heater, make
sure the electrical supply to the
water is turned OFF.
Failure to do this could result in
death, serious bodily injury, or
property damage.

10
satisfactory operation.
DO NOT ENERGIZE THE BRANCH CIRCUIT FOR ANY
REASON BEFORE THE HEATER TANK IS FILLED
WITH WATER. DOING SO WILL CAUSE THE HEATING
ELEMENTS TO BURN OUT AND VOID WARRANTY.
The factory wiring is attached to a terminal block within
the junction box. The water heater should be connected
to a separate, grounded branch circuit with over-current
protection and disconnect switch. The water heater should
be grounded in accordance with national and local codes.
BRANCH CIRCUIT
The branch circuit wire size should be established
through reference to the current edition of NFPA-70, the
National Electric Code or other locally approved source
in conjunction with the heater amperage rating. For
convenience, portions of the wire size tables from the
Code are reproduced here. The branch circuit should be
sized at 125% of the heater rating and further increase
wire size as necessary to compensate for voltage drop in
long runs.
CALCULATINGAMPERAGE/OVER-CURRENT PROTECTION
The heaters come from the factory in 2 configurations:
1. Two-wire H-2 circuit for single-element heater equipped
with high-limit control and single phase power input.
2. Four-wire H-8 circuit for dual element heater equipped
with two high-limit controls, single-phase, or three-phase
power input.
The heater with dual elements is factory-wired for
connection to a three-wire, three-phase delta branch
circuit, non-sumultaneous operation. In addition, a ground
conductor is required.
Element connection is for non-simultaneous operation.
This means only one element at a time operates. The
wiring diagram on page 10 shows the heater may be field-
converted to simultaneous element operation by moving
the red wire on “J” terminal to L-1. It is then possible
for both elements to operate at once as determined by
the thermostats. Regardless of element connection, the
heater operates in an “unbalanced” fashion.
The heater may be field-converted to single-phase
operation by moving the wire on L-3 of the terminal block
to L-2. L-3 is not used (see page 10).
The heater, now in single-phase non-simultaneous
operation, may be field-converted to single-phase
simultaneous operation by moving the red wire on terminal
“J” to L-1 (see page 10).
ELECTRICAL CONTINUED
WIRING DIAGRAMS
CIRCUIT FOR DUAL ELEMENT HEATER
H-8
H-2 CIRCUIT FOR SINGLE ELEMENT HEATERS
EQUIPPED WITH HIGH LIMIT CONTROL

11
This is an example of calculating heater amperage for
both types of element operation. From this, the branch
circuit conductor and over-current protection sizing can be
established.
The example is of a three-phase 240-volt unit with two 6
KW elements. The notations are for units field-converted
to single-phase. Check the heater model and rating plate
for actual specifications and substitute those values in the
following:
Non-Simultaneous
(Factory-Wired)
Simultaneous
(Field-Converted)
3000 / 240 = 12.5 amps* 3000/ 240 = 12.5 amps*
12.5 x 1.73 = 21.6 amps
*NOTE: As a single-phase
non-simultaneous unit.
*NOTE: as a single-phase
simultaneous unit the total
is:
12.5 x 2 = 25 amps
The rating of the over-current protection should be
computed on the basis of 125% of the total connected
load amperage. Where the standard rating and settings
do not correspond with this computation, the next higher
standard rating or setting should be selected.
Portion of Table 310-16 (NFPA-70) follows:
Allowable Ampacities of Insulated Copper Conductors
No more than three conductors in Raceway or Cable or
Direct Burial (Based on Ambient Temperature of 86˚F).
These ampacities relate only to conductors described in
Table 310-13 in Code.
For ambient temperatures that over 86˚F, see Correction
Factors (Note 13 in Code).
Size Temperature Rating of Conductor
(See Table 310-13 in Code)
AMG
MCM
140˚F 167˚F
Types:
RUW, (14-2), T, TW,
UF
Types:
RH, RHW, RUH,
(14-2), THW, THWN,
XHHW, USE
18 --- ---
16 --- ---
14 15 15
12 20 20
10 30 30
8 40 45
655 65
470 85
3 80 100
Portion of Table 310-18 follows:
Allowable Ampacities of Insulated Aluminum and Copper -
Clad Aluminum Conductors.
Not more than three conductors in Raceway or Cable
or Direct Burial (based on Ambient Temperature of 86˚F.
These ampacities relate only to conductors described in
Table 310-13 in Code.
For ambient Temperatures over 86˚F, see correction
Factors, Note 13 in Code.
Size Temperature Rating of Conductor
(See Table 310-13 in Code)
AMG
MCM
140˚F 167˚F
Types:
RUW, (12-2), T, TW,
UF
Types:
RH, RHW, RUH,
(12-2), THW, THWN,
XHHW, USE
12 15 15
10 25 25
8 30 40
640 50
4 55 65
365 75
275 90
1 85 100
OPERATION, NEXT PAGE
ELECTRICAL CONTINUED
WARNING
Before removing any access panels
or servicing the water heater, make
sure the electrical supply to the
water is turned OFF.
Failure to do this could result in
death, serious bodily injury, or
property damage.
TABLE 3
TABLE 5 TABLE 4

12
GENERAL
Refer to the Features and Components section of this
manual (page 6) for the location of components mentioned
in the instructions that follow.
NEVER turn on power to the water heater without
being certain the water heater is filled with water and a
Temperature and Pressure Relief Valve is installed in the
relief valve opening.
DO NOT TEST ELECTRICAL SYSTEM BEFORE HEATER
IS FILLED WITH WATER. FOLLOW FILLING AND
START-UP INSTRUCTIONS IN OPERATION SECTION.
FILLING THE WATER HEATER
1. Turn off the electrical disconnect switch.
2. Close the water heater drain valve.
3. Open a nearby hot water faucet to permit the air in the
system to escape.
4. Fully open the cold water inlet pipe valve allowing the
heater and piping to be filled.
5. Close the hot water faucet as water starts to flow. The
heater is now ready for START-UP and TEMPERATURE
REGULATION.
INITIAL START-UP
The following checks should be made by the installer when
the heater is placed into operation for the first time.
1. Turn off the electrical disconnect switch.
2. Open the front panel or top access cover. Check all water
and electrical connections for tightness. Also check
connections on top and/or sides of heater. Repair water
leaks and tighten electrical connections as necessary.
3. Depress the red manual reset button on each Thermostat/
ECO combination control. (See Figure 5, 6, 7, or, 8).
4. Turn on the electrical disconnect switch.
5. Observe the operation of the electrical components
during the first heating cycle. Use care as the electrical
circuits are energized.
6. Close the front panel or top access cover.
Temperature control and contactor operation should be
checked by allowing heater to come up to temperature and
shut off automatically. Use care as the electrical circuits
are energized.
DRAINING THE WATER HEATER
The water heater must be drained if it is to be shut down
and exposed to freezing temperatures. Maintenance and
service procedures may also require draining the heater.
1. Turn off the electrical disconnect switch.
2. Open the hot water valve until the water is cool, then
close the supply water inlet valve to the heater.
3. Attach hose to outlet opening of the drain valve and
direct end to drain.
4. Open a nearby hot water faucet and the heater drain
valve.
5. If the heater is being drained for an extended shutdown,
it is suggested the drain valve be left open during this
period. The hose may be removed.
Follow the FILLING instructions when restoring hot water
service.
OPERATION
DANGER
Full power is present
whenever the cabinet door
is opened.
CAUTION
PROPERTY DAMAGE HAZARD
In order to avoid water heater damage, ll tank with
water before operating.
DANGER
BURN HAZARD
HOT WATER DISCHARGE
KEEP CLEAR OF DRAIN VALVE.

13
TEMPERATURE REGULATION
THE WATER HEATER IS EQUIPPED WITH AN
ADJUSTABLE THERMOSTAT TO CONTROL WATER
TEMPERATURE. HOT WATER AT TEMPERATURES
DESIRED FOR AUTOMATIC DISHWASHER AND
LAUNDRY USE CAN CAUSE SCALDS, RESULTING IN
SERIOUS PERSONAL INJURY AND/OR DEATH. THE
TEMPERATURE AT WHICH INJURY OCCURS VARIES
WITH THE PERSON’S AGE AND TIME OF EXPOSURE.
THE SLOWER RESPONSE TIME OF CHILDREN, AGED,
OR DISABLED PERSONS INCREASES THE HAZARD
TO THEM. NEVER ALLOW SMALL CHILDREN TO USE
A HOT WATER TAP OR TO DRAW THEIR OWN BATH
WATER. NEVER LEAVE A CHILD OR DISABLE PERSON
UNATTENDED IN A BATHTUB OR SHOWER.
It is recommended that lower water temperatures be used
to avoid the risk of scalding. It is further recommended,
in all cases, that the water temperature thermostats (see
Table 6) be set for the lowest temperature, which satisfies
your hot water needs. This will also provide the most
energy efficient operation of the water heater.
Table 6 shows the approximate time-to-burn relationship
for normal adult skin. The thermostats on your water
heater have a linear relationship between degrees
of angular rotation and the corresponding change in
temperature. Thus, rotating the temperature adjustment
indicator 30 angular degrees will result in a 10˚F change in
water temperature.
Water
Temperature
Time to produce 2nd & 3rd Degree Burns on
Adult Skin
181˚F INSTANTANEOUS
160˚F ABOUT 1/2 SECOND
150˚F ABOUT 1-1/2 SECONDS
140˚F LESS THAN 5 SECONDS
130˚F ABOUT 30 SECONDS
120˚F MORE THAN 5 MINUTES
TEMPERATURE ADJUSTMENT
The water heater is supplied with thermostats that may
come from different manufacturers and have different
temperature indications as described next:
APCOM THERMOSTATS
H-8 circuit thermostats have three designated set points: LO,
MED, and HI (see Figure 5). The approximate equivalent
temperatures for these three settings are:
LO = 140˚F
MED = 160˚F
HI = 181˚F
These thermostats are set from the factory at the LO setting.
The over temperature device (ECO High-Limit) attached
to each thermostat has a manual reset. The H-2 circuit
thermostat is adjustable from approximately 130˚F to 170˚F
(see Figure 6). these thermostats are set from the factory at
approximately the 125˚F setting. The over-temperature device
(ECO High-Limit) attached to each thermostat has a manual
reset.
THERMODISC THERMOSTATS
H-8 circuit thermostats are adjustable from approximately
120˚F (lowest setting) to 181˚F (highest setting) (see Figure
7). The H-2 circuit thermostat is adjustable from approximately
110˚F to 170˚F (see Figure 8). These thermostats are set at
approximately the 125˚F setting. The over-temperature device
(ECO High-Limit) attached to each thermostat has a manual
reset.
NOTE: It is not necessary to adjust the upper thermostat
for a dual-element unit; however, if it is adjusted above
the factory set-point of 125˚F, it is recommended that it
not be set higher than the lower thermostat setting.
To change the temperature setting:
1. DANGER: Turn off the heater electrical supply. Do not
attempt to adjust the thermostat with power on.
2. Open the junction box door (for upper thermostat of
dual-element water heater only) and/or remove the
(lower) thermostat access panel. Do not remove the
plastic personnel protectors covering the thermostats.
The thermostat is factory pre-set at 125˚F.
3. Using a flat-head screwdriver, rotate the adjusting know
to the desired temperature setting.
4. Replace the covers and access panels, and turn on the
heater electrical supply.
DANGER
Water temperature over 125˚F can
cause severe burns, resulting in
severe injury or death.
Children, the elderly, and physically
or mentally disabled are at highest
risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting valves are
available.
Read instruction manual for safe
temperature setting.
TABLE 6
FIGURE 7 FIGURE 8
FIGURE 5 FIGURE 6

14
GENERAL
Periodically, the drain valve should be opened and the
water allowed to run until it flows clean. This will help to
prevent sediment buildup in the tank bottom.
Periodically, check the Temperature and Pressure Relief
Valve to ensure that it is in operating condition. Lift the
lever at the top of the valve several times until the valve
seats properly and operates freely.
Water heater maintenance includes periodic tank flushing
and cleaning, and removal of lime scale from the heating
element.
MAINTENANCE
DANGER
BURN HAZARD
HOT WATER DISCHARGE
KEEP CLEAR OF DRAIN VALVE.
TROUBLESHOOTING CHECKLIST
CHECKLIST
Before calling for service, check the following points to see
if cause of trouble can be identified and corrected.
Reviewing this checklist may eliminate the need of a
service call and quickly restore hot water service. See
page 6 in this manual to identify and locate water heater
components.
NOT ENOUGH OR NO HOT WATER
1. Be certain the electrical disconnect switch serving the
water heater is in the ON position.
2. Check the fuses.
The electrical disconnect switch usually contains
fuses.
3. If the water was excessively hot and is now cold, the
high limit switch may have activated.
Large demands require a recovery period to restore
water temperature.
4. The capacity of the heater may have been exceeded by
a large demand for hot water.
5. Cooler incoming water temperature will lengthen the
time required to heat water to the desired temperature.
6. Look for hot water leakage.
7. Sediment or pipe scale may be affecting water heater
operation.
ABNORMAL SOUNDS
1. Sediment or lime scale accumulations on the elements
causes sizzling and hissing noises when the heater is
operating.
WARNING
Before removing any access panels
or servicing the water heater, make
sure the electrical supply to the
water is turned OFF.
Failure to do this could result in
death, serious bodily injury, or
property damage.
TROUBLESHOOTING/ LEAKING, NEXT PAGE

15
WATER LEAKAGE IS SUSPECTED
Refer to Leakage Checkpoint (next section).
1. Check to see if the heater drain valve is tightly closed.
2. If the outlet of the relief valve is leaking, it may be due to
one or more of the following:
Excessive water temperature
Faulty relief valve
Excessive water pressure
3. Excessive water pressure is the most common cause
of relief valve leakage. It is often caused by a “closed
system.” See Closed Water Systems and Thermal
Expansion in the “Installation” section of this manual.
4. Examine the area around the element for gasket
leakage.
Tighten the elements, or (if necessary) follow the
WATER AND LIME SCALE REMOVAL procedure to
replace the gaskets.
IF UNABLE TO IDENTIFY OR CORRECT THE SOURCE
OF MALFUNCTION
1. Turn the power supply to the water heater off.
2. Close the supply water inlet valve to the heater.
3. Contact a Qualified Service Agency in your area. Call
the toll free phone number on the back cover of this
Instruction Manual for assistance in locating a service
agency in your area.
REPLACEMENT PARTS
Call the phone number on the back cover of this Instruction
Manual for assistance in locating replacement parts. When
ordering parts, specify complete model no. (see rating
plate), quantity, and name of the part desired. Standard
hardware items should be purchased locally.
TROUBLESHOOTING CHECKLIST, CONTINUED
LEAKAGE CHECKPOINTS REPLACEMENT PARTS
Num. Part Name Leakage Point(s)
1T&P Valve
Leak from Plumbing Connec-
tion Point/ Leak from Weld to
Outer Tube/ Leak from Weld
to Tank Head
2* 1 7/16” - 14 Male
Nipple
Leak from Plumbing Connec-
tion Point/ Leak from Weld to
Outer Tube/ Leak from Weld
to Tank Head
5Elec. Element
Flange Leak from Weld to Tank Shell
7 Drain Valve
Leak from Valve/ Leak at
Connection Point/ Leak from
Weld to Tank Shell``
1
2* 2*
4
5
6
7
3
Num. Part Name Item Number
1T&P Valve VALVE-TP-WATTS-100XL8
3Junction Box
Cover CVR_JUNCTION BOX
4 Thermostat ELEC_THERMOSTAT
5Heating Element *SEE TABLE 7 ON NEXT
PAGE FOR OPTIONS
6Thermostat
Bracket ELEC_THERM. BRACKET
7 Drain Valve VALVE_DRAIN
*Fits Watts 3/4 LF301 Dielectric Union (included with unit).

16
REPLACEMENT HEATING ELEMENTS
VOLTAGE
TOTAL KW
INPUT
ELEMENT
WATTAGE PART NUMBER
120
1.5 1500 ELEC_EL-120V1500W
2.0 2000 ELEC_EL-120V2000W
2.5 2500 ELEC_EL-120V2500W
3.0 3000 ELEC_EL-120V3000W
277
1.5 1500 ELEC_EL-277V1500W
2.0 2000 ELEC_EL-277V2000W
2.5 2500 ELEC_EL-277V2500W
3.0 3000 ELEC_EL-277V3000W
4.5 4500 ELEC_EL-277V4500W
6.1 6100 ELEC_EL-277V6100W
208
1.5 1500 ELEC_EL-208V1500W
2.0 2000 ELEC_EL-208V2000W
2.5 2500 ELEC_EL-208V2500W
3.0 3000 ELEC_EL-208V3000W
4.5 4500 ELEC_EL-208V4500W
5.0 5000 ELEC_EL-208V5000W
5.5 5500 ELEC_EL-208V5500W
6.1 6100 ELEC_EL-208V6100W
240
1.5 1500 ELEC_EL-240V1500W
2.0 2000 ELEC_EL-240V2000W
2.5 2500 ELEC_EL-240V2500W
3.0 3000 ELEC_EL-240V3000W
4.5 4500 ELEC_EL-240V4500W
5.0 5000 ELEC_EL-240V5000W
5.5 5500 ELEC_EL-240V5500W
6.1 6100 ELEC_EL-240V6100W
480
2.5 2500 ELEC_EL-480V2500W
3.0 3000 ELEC_EL-480V3000W
4.5 4500 ELEC_EL-480V4500W
5.0 5000 ELEC_EL-480V5000W
6.1 6100 ELEC_EL-480V6100W
TABLE 7

17
COMMERCIAL ELECTRIC WATER
HEATER LIMITED WARRANTY
EFFECTIVE
For 3 Years, in the event of a tank leak, we will repair or, at our discretion, replace the defective water heater. For 1 Year,
in the event of part failure, we will repair or, at our discretion, replace the defective part. We warrant this product against
defects in materials or workmanship as described in this document if installed within the United States or Canada and
provided the product remains at its original place of installation. Warranty coverage begins the date of installation OR the
date of manufacture if installation cannot be veried.
WHAT IS COVERED
Subject to these terms, in the event of defect in materials and/or workmanship resulting in a tank leak during the rst three
years, we will: Replace the water heater should the tank leak. Subject to these terms, in the event of a defect in materials
and/or workmanship appearing during the rst year, we will: Repair or, at our discretion, replace any part of the water heater
covered under this limited warranty excluding parts subject to normal maintenance (Example: anode rod, lter, etc...).
WHAT IS NOT COVERED
• Problems caused by improper: Voltage, wiring, fusing
• Failure to follow applicable codes
• Failure to follow printed instructions
• Abuse, misuse, accident, re, ood, Acts of God
• Improper installation, sizing, delivery, or maintenance
• Claims related to rust, noise, smell, or taste of water
• Failure to conduct authorized factory start up if required
• Alterations to the water heater
• Non-outdoor heaters installed outdoors
• Damages due to a failure to allow for thermal expansion
• Heat-exchanger failure due to lack of adequate/ proper supply of water
• Heaters moved from their original location
• Service trips to explain proper installation, use, or maintenance of the product/unit or to describe compliance
requirements under applicable codes and regulations
• Charges related to accessing your heater including, but not limited to: Door/wall removal, equipment rental, etc...
• Replacement parts after expiration of this warranty
LIMITATION
NOTWITHSTANDING ANYTHING ELSE TO THE CONTRARY, THIS IS YOUR SOLE AND EXCLUSIVE WARRANTY.
ALL OTHER WARRANTIES, INCLUDING A WARRANTY OF MERCHANTABILITY OR FITNESS FOR PARTICULAR
PURPOSE, ARE EXPRESSLY DISCLAIMED. SELLER SHALL NOT BE LIABLE FOR ANY CONSEQUENTIAL,
INCIDENTAL, SPECIAL, PUNITIVE, OR OTHER INDIRECT DAMAGES. TOTAL LIABILITY ARISING AT ANY TIME SHALL
NOT EXCEED THE PURCHASE PRICE PAID, WHETHER BASED ON CONTRACT, TORT, STRICT LIABILITY, OR ANY
OTHER LEGAL THEORY.
SERVICES INQUIRIES:
For service inquiries, call the telephone number listed below. Be prepared to provide the following information: Name,
address, and telephone number; the model and serial number of the water heater; proof of installation; and a clear description
of the problem.
For your records, ll in the product:
Serial: ___________________
Model: ___________________
Heat-o, Inc., 15 Megan Ct., P.O. Box 612, Uxbridge, MA 01569 USA
Tel: [phone] | Fax: [phone] | www.heat-o.com

18

HEAT-FLO, INC.
P.O. BOX 612
UXBRIDGE, MA 01569
508-278-2400
www.heat-o.com