Bock Water heaters EZ FIT Atmospheric Gas EZ 75-76N User manual

WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause serious
injury or property damage. Refer to this
manual. For assistance or additional
information, consult a qualified installer or
service agency.
WARNING
If the information in these instructions is not
followed exactly, a fire or explosion may result
causing property damage, personal injury or
death.
WARNING
Do not install on combustible flooring. Install
in accordance with all local codes. In the
absence of local codes, refer to ANSI
223.1/NFPA 54 and/or CSA B149.1.
CA TION
The recommended temperature for normal
residential use is 120°F. The dial on the aquastat
does not always reflect the out-coming water
temperature and it could occasionally exceed
120°F. Variation in out-coming temperature
could be based on factors including but not
limited to usage patterns and type of installa-
tion. Test water at the tap nearest to the water
heater. See page 9 for measuring the out-
coming water temperature.
WARNING
Hotter water increases the risk of scald injury.
Before adjusting the water temperature setting,
read this instruction manual. Temperatures at
which injury occurs vary with the person’s age
and the length of exposure. The slower
reaction time of children, elderly or physically
or mentally challenged persons increases the
scalding hazard to them. It is recommended
that lower water temperatures be used where
these exposure hazards exist. Households with
small children or invalids may require a
temperature setting less than 120°F to prevent
accidental contact with hot water. To produce
less than 120°F, use point-of-use
temperature limiting devices.
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of the water system, automatic temperature
limiting devices must be used on all lines to
water taps.
WARNING
Flammable vapors may be drawn to this water
heater from other areas of the structure by air
currents. Do not store or use any flammable
liquids in the vicinity of this heater.
WARNING
Water heater blankets may restrict air flow to
the water heater and cause fire, asphyxiation,
personal injury or death.
THIS MANUAL HAS BEEN PREPARED T
ACQUAINT Y U WITH THE INSTALLATI N,
PERATI N, AND MAINTENANCE F Y UR
WATER HEATER AND T PR VIDE IMP RTANT
SAFETY INF RMATI N.
Read all instructions thoroughly before
attempting installation or operation of your
water heater. Keep these instructions for future
reference.
Local plumbing and electrical codes must be
followed in the installation of this water
heater. In the absence of a local code use the
UNIFORM PLUMBIN CODE and the NFPA
Code. Local codes may supersede instructions
in this installation manual.
These instructions are a guide for the correct
installation of the water heater. The manufac-
turer will not be liable for damages caused by
failure to comply with the installation and
operating instructions outlined on the
following pages.
Installation, testing, and replacement of gas
piping, appliances, or accessories, and repair
and servicing of equipment, shall be
performed only by a qualified agency.
FAILURE T F LL W THESE INSTRUCTI NS
R ALL APPLICABLE BUILDING C DES
AND REGULATI NS V IDS THE WARRANTY
N THIS WATER HEATER.
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Warranty, Registration Card and Parts List are included.
Homeowner: Please remember to return the Registration Card!
To the Consumer:
Please read these and all component
instructions and keep for future reference.
To the Installer:
Please attach these instructions
next to the water heater.
Rev4 6/16
Atmospheric Gas Instruction Manual
23405
EZ 75-76, EZ 100-76

Page 2 Atmospheric Gas
IMPORTANT SAFETY INSTR CTIONS
FOR YO R SAFETY!
- Do not store or use gasoline or other flammable vapors and liquids in the
vicinity of this or any other appliance.
- WHAT T D IF Y U SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your
building.
• Immediately call your gas supplier from a neighbor’s phone.
Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
- Installation and service must be performed by a qualified installer,
service agency or the gas supplier.
SAVE THESE INSTR CTIONS
WARNING
If the information in these instructions is not followed exactly, a fire or
explosion may result causing property damage, personal injury or death.
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DANGER
Water heaters utilizing Liquefied Petroleum gas (LP) are different from
natural gas models. A natural gas heater will not function safely on LP gas
and vice versa. To avoid possible equipment damage, personal injury or
fire: D N T connect this water heater to a fuel type not in accordance
with the rating label. These units are only certified for a single fuel type.
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DANGER
Failure to install the draft hood and properly vent the water heater to the
outdoors as outlined in this manual can result in unsafe operation of the
water heater. To avoid the risk of fire, explosion, or asphyxiation from
carbon monoxide, never operate this water heater unless it is properly
vented and has adequate air supply for combustion. Be sure to inspect
the vent system for proper installation at initial start-up; and at least
annually thereafter. See the Maintenance section for more information.
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Atmospheric Gas Page 3
TABLE OF CONTENTS
Section I: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Section II: General Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Section III: Pre-Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Section IV: Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Section V: Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Section VI: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Section VII: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Section VIII: Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Section IX: Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Model
Storage ( AL)
Rated Input
(BTU/HR)
EZ 75-76N 75 76,000 73 133 69.19 65.38 26.00 58.25 14.50 11.00 4.00 1.00 1.00 0.50 391
EZ 100-76N 100 76,000 73 153 69.81 66.00 28.00 57.94 14.50 11.00 4.00 1.00 1.00 0.50 485
Table 1: Dimensions
Page 4 Atmospheric Gas
SECTION I: SPECIFICATIONS
OFF
WARM
VERYHOT
CAUTION
HOTTERWATER
INCREASESTHE
RISKOF
SCALDING
INJURY
WARNING
READALLINSTRUCTIONSBEFORELIGHTING
OFF
PILOT
ON
Cold
Hot
Anode Rod (2)
Draft Hood
T&P Relief
Valve
Drain
Gas/Temp.
Control
A
E
D
C
F
G
B
Figure 1: All Models
Recovery @ 100
o
F
Rise ( PH)
1st Hr. Delivery @
100
o
F Rise ( AL)
A
B
C
D
E
F
Inlet Conn. Dia.
Outlet Conn. Dia.
as Conn. Dia.
Shipping Weight
(LBS)
DIMENSIONS (inches)
For LP models change suffix "N" to "LP"
Working Pressure: 150 PSI (1034 kPa)
Test Pressure: 300 PSI (2068kPa)
For natural gas: anifold pressure = 4" W.C. (1.00 kPa); Inlet pressure range 5-14" W.C. (1.25 - 3.49 kPa)
For propane gas: anifold pressure = 10" W.C. (2.49 kPa); Inlet pressure range 11-14" W.C. (2.74 - 3.49 kPa)
T&P valve installed
All Bock products meet or exceed current ASHRAE standards.
These products are design certified by UL (Underwriters Laboratories) and meet ANSI Z21.10.3 requirements for operation up to 180°F (82°C).
Approved for use as an automatic circulating tank water heater or automatic storage water heater.
WARNING: Do not install on combustible flooring. Installation shall be in accordance with all national and/or local codes.
In the absense of local codes, refer to NFPA 54 and/or CSA B149.1.
CAUTION: The recommended maximum hot water temperature setting for normal residential use is 120°F (49°C). Bock recommends a
tempering valve or anti-scald valve be installed and used according to the manufacturer's directions to prevent scalding.

Atmospheric Gas Page 5
APPROXIMATE
TEMPERATURE/TIME
RELATIONSHIPS TO
SCALDIN
120°F More than 5 minutes
125°F 1 1⁄2 to 2 minutes
130°F About 30 seconds
135°F About 10 seconds
140°F Less than 5 seconds
145°F Less than 3 seconds
150°F About 1 1⁄2 seconds
155°F About 1 second
Table 2: Scald Tem erature/Time Relationshi s
SECTION II: GENERAL INFORMATION
WHEN YOU RECEIVE YOUR NEW WATER HEATER
Check the new equipment to see if all components are in good condition. If damage is
observed or parts appear to be missing, contact your wholesaler.
WATER TREATMENT/FILTRATION
In areas where poor water conditions are suspected (i.e. lime, iron, and other minerals), it is
essential that the water be tested and appropriate action taken to prevent damage to the
water heater and ensure the quality of the water.
TEMPERATURE CONTROL
The water heater is equipped with a gas thermostat to monitor tank temperature and control
operation of the main burner. For domestic hot water, the proper temperature setting is 120°F.
For commercial applications, the maximum approved temperature setting is 180°F.
A built in, non-cycling Energy Cut-Off (ECO) is standard on all gas thermostats. In the event
that the water temperature becomes excessive (200°F), the ECO will shut off all gas to the
water heater. If an ECO has detected an over-temperature condition and has opened, the
control will not function and a replacement will be required.
The thermostat is factory set at 120°F. See Figure 6 for thermostat letter and temperature
relationships. If hotter water is required a tempering device or anti-scald device must be
installed at the domestic hot water outlet of the heater or at the point of use. Table 3 details
the approximate relationship of water temperature and time with regard to scald injury. It is
important for the user to understand the necessity of tempering or anti-scald devices when
using hotter water in domestic water heating systems.
CAUTI N: Hot water in excess of 120°F can cause scalding!
Bock recommends a tempering valve or anti-scald valve be installed and used according to
the manufacturer’s directions to prevent scalding. Many state and local codes now require
installation of these devices. The tempering valve or anti-scald valve will ensure potable
water temperatures at the desired set point with a higher degree of accuracy.
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Page 6 Atmospheric Gas
SECTION II: GENERAL INFORMATION (cont.)
ANODE ROD
The anode rod is used as a sacrificial element within the volume of the storage tank. The
purpose of the magnesium anode rod is to protect the inside of the tank against corrosion.
Anode rods should be inspected twice in the first year and at least yearly once a time interval
for inspection has been developed. Water conditions can influence the consumption rate of
the anode rods. Please see the Maintenance section of this manual for instructions on how to
change the anode rods.
CAUTI N
Hydrogen gas is produced in a hot water system served by the heater that has not
been used for a long period of time (2 weeks or more). Hydrogen gas is extremely
flammable. 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. When hydrogen is present,
there will probably be an unusual sound such as air escaping through the pipe as the
water begins to flow. There should be no smoking or open flame near the faucet at the
time it is open.
TEMPERATURE AND PRE URE RELIEF VALVE (T&P)
CAUTI N
To reduce the risk of excessive pressures and temperatures in this water heater, install
temperature and pressure protective equipment required by local codes and no less
than a combination temperature and pressure relief valve certified by a nationally
recognized testing laboratory that maintains periodic inspection of production of listed
equipment or materials, as meeting the requirements for Relief Valves and Automatic
Gas Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22. This valve must be
marked with a maximum set pressure not to exceed the marked maximum working
pressure of the water heater. Install the valve in an opening provided and marked for
this purpose in the water heater, and orient it or provide tubing so that any discharge
from the valve exits only within 6 inches above, or at any distance below, the
structural floor, and does not contact any live electrical part. The discharge opening
must not be blocked or reduced in size under any circumstances.
CAUTI N
Scalding injury and/or water damage can occur from either the manual lifting of the
lever or the normal operation of the T&P valve. If it is not piped to a proper drain. If the
valve fails to flow water or reseat, call your plumber.
The T&P valve is factory installed. A discharge drain tube must be installed (responsibility
of the installer) and shall terminate plain, not threaded, 6 inches above the floor drain.
The drain tube material must be approved for temperatures of 120o F or greater and a
pressure of 150 PSI or greater.
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Atmospheric Gas Page 7
SECTION II: GENERAL INFORMATION (cont.)
BACKFLOW PREVENTER (CLO ED Y TEM)
Some local municipal codes and ordinances require the use of these devices on potable
(domestic) water lines. Where backflow preventers are required, it will be necessary to install
a thermal expansion tank (designed for use with potable water) in order to prevent pressure
build up in the water heater and associated piping, which could cause the T&P
valve to discharge. Follow the expansion tank manufacturer’s recommendations when
selecting a tank for your hot water system.
Note: Working pressure of the water heater is 150 P I. Do not exceed 150 P I.
SECTION III: PRE-INSTALLATION
LOCATION
CAUTI N
This water heater must be located in an area where leakage of the tank, water line
connections, or the temperature and pressure relief valve will not result in damage to
the area adjacent to the water heater or to lower floors of the structure. When such
location cannot be avoided, a suitable drain pan must be installed under the water
heater. The drain pan depth must be suitable for draining and collecting water. The
drain pan can be purchased from your plumbing professional. The drain pan must be
piped to an adequate drain and all drain piping must be at least 0.75” in diameter
and pitched for proper drainage.
CAUTI N
D N T store or use gasoline or other flammable, combustible, or corrosive vapors
and/or liquids in the vicinity of the water heater or any other appliance.
IF Y U SMELL GAS:
• D N T try to light any appliance.
• D N T touch any electric switch; do not use any telephone in your building.
• Immediately call your gas supplier from a telephone in another building. Follow your
gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
D N T PERATE THE APPLIANCE UNTIL THE LEAKAGE IS C RRECTED!
CAUTI N
Do not drop water heater or lay heater down on its side. Move the water heater into
position by sliding or using an appropriately sized hand truck.
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Page 8 Atmospheric Gas
SECTION III: PRE-INSTALLATION (cont.)
NOTE: Locate the heater so it is not subject to physical damage from moving vehicles or
flooding. Do not locate the water heater in a room where swimming pool chemicals or large
quantities of water softener salt are kept. Installing a water heater
in this environment will result in premature failure of tank and
burner components due to corrosion caused by these elements
diffusing into the air.
DO NOT IN TALL THE WATER HEATER ON COMBU TIBLE
FLOORING. Place on noncombustible flooring and maintain
clearances prescribed by this manufacturer and per code NFPA 54. If
the water heater must be located on combustible flooring it must be
raised off the floor with a layer of 4'' concrete block laid so the air
holes are aligned as shown in Figure 2. Consult with local code
officials before using this method. Please consult local codes, NFPA
54 and/or contact Bock Water Heaters with questions concerning
proper flooring materials. Leave adequate room for periodic maintenance of heater and burner.
The water heater should be placed as near to the chimney as practical in order to keep vent
connector length to a minimum. Consult National Fuel as Code for proper vent configuration.
Minimum clearance to combustible construction is: IDE 6"; BACK 6"; FRONT 24";
DRAFT HOOD; 18". The installation of this water heater must conform with local
codes and ordinances. In the absence of local codes, the installation must comply
with the National Fire Protection Association (NFPA 54) Code.
COMBU TION AND VENTILATION AIR
The water heater must be installed in a location with an adequate air supply for combustion,
ventilation and draft control. Unsafe levels of carbon monoxide (CO), condensation and
sooting may result if the room does not have an adequate air supply. See “National Fuel as
Code (NFPA 54)” or the discussions of “Unconfined Space” and “Confined Space” below. Poor
ventilation will also result in hot spots around the heater. Temperatures over 90°F near the
water heater generally indicate a lack of ventilation.
UNCONFINED PACE
Unconfined space is defined by NFPA 54 as a space with a volume greater than 50 cubic feet
(during typical use) per 1000 BTUH of the total combined input of all fuel burning appliances
in the space. Rooms leading directly to the installation space through doors that cannot be
closed can be considered part of the space. Exception: Buildings with full vapor barriers, tight
doors and windows or air infiltration rates of less than 0.35 air changes per hour will be
considered a confined space and require additional air supplies.
CONFINED PACE
Confined space is defined by NFPA 54 as a space with a volume less than 50 cubic feet (during
typical use) per 1000 BTUH of the total combined input of all fuel burning appliances in the
space. Buildings or rooms of unusually tight construction are also considered a confined space.
See “Unconfined pace: Exception”.
When installing fuel burning appliances in a confined space, air must be supplied to that
space from either inside or outside of the building as conditions allow.
A. Inside Air upply: A confined space shall be provided with two permanent openings; one
within 12 inches of the top and one within 12 inches of the bottom of the enclosure. These
openings shall lead directly to room(s) of sufficient volume so that the combined volume of
all the space meets the criteria for unconfined space. Each opening shall have a minimum free
area of 1 square inch per 1000 Btu/hr of the combined total input of all fuel burning
appliances in the space. Each opening shall have an area of not less than 100 square inches or
a minimum dimension of not less than 3 inches.
Figure 2

Atmospheric Gas Page 9
SECTION III: PRE-INSTALLATION (cont.)
CONFINED PACE (CONT.)
B. Outside Air upply: Confined spaces shall be provided with two permanent openings; one
within 12 inches of the top and one within 12 inches of the bottom of the enclosure. These
openings shall communicate directly, or by ducts, with the outdoors or spaces that
communicate with the outdoors.
1.) Leading directly to the outside or through vertical ducts: Each opening shall have a
minimum free area of one square inch per 4000 Btu/hr of total input rating of all equipment
in the enclosure.
2.) Leading to outside through horizontal ducts: Each opening shall have a minimum free
area of one square inch per 2000 Btu/hr of total input rating of all equipment in the enclosure.
Note: All ducts shall have the same cross sectional area as the free area of each opening to
which they connect. The minimum dimensions of all ducts shall not be less than three inches.
Powered combustion air supplies are also commercially available and may be used.
LOUVER & GRILLE
In calculating the free area of an opening, consideration must be given to the blocking effects
of louvers or grilles protecting the opening. Any screens used must be no finer than 1⁄4inch
mesh. If the free area of a louver or grille is known, this should be used in calculating the size
of opening required. If free area is unknown, it may be assumed that wood louvers will have
20 to 25% free area and metal louvers and grilles will have 60 to 75% free area. Louvers and
grilles should be fixed in the open position or interlocked with the equipment so that they
open automatically during equipment operation.
VENTING
The water heater shall be located as close to the chimney as practical. Long lateral runs will
result in intermittent combustion problems and unsafe operating conditions. Total vent
height should be a minimum of 6 feet. Shorter vent heights could result in unstable draft and
nuisance lock outs.
The venting system should be sized according to National Fuel as Code: NFPA 54/ANSI
Z223.1 (most recent edition) using the “Natural” column. If you do not have a copy of this
code one can be obtained at www.NFPA.org for a nominal fee. Copies of the NFPA venting
tables are also reprinted in the Bock Engineering Manual available from your Bock Represen-
tative or by download from www.bockwaterheaters.com. Note: Do not reduce vent size more
than one size smaller than the vent connector supplied with the heater. If vent size must be
reduced one size, use full size vent connectors on the vent hood and reduce vent size as far
from the water heater as practical. B vent, L vent or multi-fuel venting may be used. Vent
tables supplied by the vent manufacturer may also be used in sizing the vent system.
Venting system must be capable of producing –0.02" WC (inches of water column) draft
minimum. If draft of –0.02" WC cannot be produced with an existing vent system, a draft
inducer may be required. Installations common vented with large vent hood equipped
appliances such as heating boilers may require vent dampers on the heating boiler connectors
for proper vent operation during no-heating season.
Check the building for items that can cause severe negative pressure problems such as large
exhaust fans. If these devices are installed in the same building check for their effect on draft
and combustion. All fuel burning appliances must be isolated from the effects of these devices
to operate properly. Failure to address this issue will result in unsafe operation and shorten
appliance life spans.
Your Bock water heater may also be operated with a power venter. The power venter must be
properly sized and adjusted to provide proper draft. Power venter wiring must turn on the
power venter on a call for heat and must prove venter operation before allowing the burner to
start. Refer to the power venter instructions for proper wiring and adjustment procedures.

Page 10 Atmospheric Gas
SECTION IV: INSTALLATION
WATER CONNECTION
CAUTI N
This water heater incorporates fittings that contain a nonmetallic lining. D N T apply
heat to these fittings when making sweat connections to the heater. Sweat tubing to
an adapter before securing adapter to any fittings on water heaters.
ALL PIPIN SHOULD CONFORM TO LOCAL CODES AND ORDINANCES. It is highly
recommended that unions and shut-off valves are installed at the potable water connections
to allow for isolation and/or movement during service. All piping should be adequately
insulated with an approved material to minimize heat loss.
POTABLE WATER CONNECTION
THE WATER HEATER MU T BE FILLED WITH WATER BEFORE LIGHTING THE
BURNER.
1) Close the main water supply valve before continuing with the installation. After the main
water supply is shut-off, relieve the water line pressure by opening a faucet. Once the pressure
has been relieved, close the faucet. The “Cold” and “Hot” potable water connections are
labeled on the water heater. Install a union and shut-off valve at both potable water
connections. All piping should be 3/4” diameter new copper or larger. A tempering valve or
anti-scald valve should be installed at the potable water outlet and used according to the
manufacturer’s specifications to prevent scalding.
2) If a backflow preventer is required in the cold water supply, a properly sized expansion tank
must be installed to control thermal expansion. Do not operate the water heater in a closed
system without installing a thermal expansion tank. Follow the expansion tank manufactur-
er’s recommendations when selecting a tank for your system.
3) Following installation of the water lines, open the main water supply valve and fill the
water heater. Open several hot water faucets to relieve air from the system. After water is
flowing through the faucets and the system is void of air, close the faucets and check for water
leaks in the system.
Note: Do not try to heat hard water as this will drastically reduce heater life. Install a water
softener or other scale reducing water treatment system if the water heater is being installed in
a hard water area (water hardness higher than seven grains).
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Atmospheric Gas Page 11
SECTION IV: INSTALLATION (cont.)
GA CONNECTION
CAUTI N
Do not use this water heater with any gas other than the type listed on the rating label.
Check the rating label on the front of the water heater and make sure the gas to be used
matches the gas stated on the rating label. Consult your local gas company or Bock Water
Heaters with any questions.
A manual valve, union, and a sediment trap should all be provided in front of the gas
thermostat. All gas piping must conform to local codes and/or the National Fuel as Code,
ANSI 223.1/NFPA 54 (latest edition).
Supply piping should be sized according to the charts found in the National Fuel as Code
for natural gas applications.
Note: When sizing the gas piping to the heater, make sure that the pressure at the valve is
sufficient when all other appliances are operating. Undersized gas piping will reduce water
heater performance and life as well as result in nuisance lockouts. Also verify that the gas
service and meter are sized properly for the load.
as piping should be carried oversize, i.e.: 3⁄4inch or 1 inch or larger for 1⁄2inch valve to
within 2 feet of the valve itself. This sustains pressure at the valve during start-up to prevent
flashbacks caused by momentary pressure loss. For natural gas, 5" W.C. pressure must be
maintained upstream of the gas valve during operation. For LP gas, a minimum of 11" W.C.
must be maintained upstream of the gas valve. A 1⁄8inch NPT pipe connection should be
installed upstream of the manual shut-off valve to check incoming gas pressure.
During pressure testing of the gas supply piping, close the manual gas shut-off valve to the
water heater. Test pressure shall not exceed 1⁄2PSI (14" W.C). The gas valve is only rated for
1⁄2PSI . To test at pressure greater than 1⁄2PSI , close the manual shut-off valve and
disconnect the gas operating valve.
Turn on gas and inspect piping for leaks by “painting” each joint with soap and checking for
bubbles. Do not use open flame. The pipe thread compound that is used on gas piping must be
of the type resistant to propane gas. Do not use teflon tape on gas piping. Note: For high
altitude applications (above 2000 feet) contact Bock Water Heaters.
DRAFT HOOD AND VENTING
This water heater must be installed with the factory supplied draft hood. See Figure 3 for
placement. Vent connectors must be attached to the draft hood to connect the water heater to
the gas vent or chimney. The vent connector must be the same diameter as the outlet of the
draft hood. Never use a smaller diameter vent connector. Horizontal vent connectors must be
pitched upward to the chimney at least 1/4” per foot of length. Vent connector joints should
be securely fastened with sheet metal screws. For further specifications, see the National Fuel
as Code (NFPA 54).
DANGER
Substitution, elimination or relocation of the draft hood will result in unsafe operation
and void the warranty of your water heater. Improper venting or misuse of the draft
hood can result in unsafe operation causing bodily injury, explosion, fire or death. To
avoid the risk of fire, explosion, or asphyxiation from carbon monoxide, NEVER operate
this water heater unless it is properly vented and has an adequate air supply.
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Page 12 Atmospheric Gas
Expansion Tank
Union
Shut-O Valve
Draft Hood
Cold Water
Supply
Hot Water Outlet
to Mixing Valve
(not shown)
Union
Shut-O Valve
Anode (1 of 2)
Vent to Chimney
(Pitch up 1/4" per Foot)
Backow
Preventer (optional)
T&P Relief
Valve
Relief Valve
Discharge Line
to Floor Drain
Gas Supply
Gas Shut-O Valve
Union
Gas
Thermostat
Sediment
Trap
Drain
Valve
Heat Trap (6" min)
Heat Trap
(6" min)
Figure 4: Recommended Water, Gas, Vent Connections
SECTION IV: INSTALLATION (cont.)
DRAFT HOOD IN TALLATION
1. Locate the two predrilled holes in the top pan.
2. Align and insert the draft hood legs (without screw holes)
into the holes in the top pan.
3. Using a drill and the two sheet metal screws (supplied),
fasten the other two legs (with screw holes) to the top pan.
The draft hood should now be securely joined to the water
heater.
Figure 3: Install Draft Hood

Atmospheric Gas Page 13
SECTION V: OPERATION
This appliance has a pilot which must be
lighted by hand. When lighting the pilot,
follow these instructions exactly.
A.
STOP! Read the safety information above
on this label.
1.
Set the thermostat to lowest setting.2.
Turn gas control knob clockwise
to "OFF."
3.
Wait five (5) minutes to clear out any gas.
If you then smell gas, STOP! Follow "B"
in the safety information above on this label.
If you don't smell gas, go to the next step.
4.
Remove both access panels and insulation
located below the gas control.
5.
BEFORE LIGHTING smell all around the
appliance area for gas. Be sure to smell next
to the floor because some gas is heavier than
air and will settle on the floor.
B. C.
D.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.
Do not touch any electric switch; do not use
any phone in your building.
Immediately call your gas supplier from
a neighbor's phone. Follow the gas supplier's
instructions.
Use only your hand to push in or turn the
gas control knob. Never use tools. If the
knob will not push in or turn by hand, don't
try to repair it, call a qualified service
technician. Force or attempted repair
may result in a fire or explosion.
6. Find pilot - follow metal tube from
gas control. The pilot is mounted
on a bracket at an upward angle.
7. Turn gas control knob
counterclockwise to "PILOT."
9. Return both access panels and the insulation
to their respective locations.
10. Turn gas control knob counterclockwise
to "ON."
11. Set thermostat to desired setting.
8. Push in gas control knob or pilot gas button all
the way and hold in. Immediately light
the pilot with a match or multi-purpose lighter.
Continue to hold the control knob in for about
one (1) minute after the pilot is lit. Release
knob or button and it will pop back up. Pilot
should remain lit. If it goes out, repeat steps 3
through 8.
Do not use this appliance if any part has been
under water. Immediately call a qualified
service technician to inspect the appliance
and to replace any part of the control system
and any gas control which has been under water.
WARNING: If you do not follow these instructions exactly, a fire or
explosion may result causing property damage, personal injury or loss
of life.
If you cannot reach your gas supplier, call
the fire department.
If the knob does not pop up when released,
stop and immediately call your service
technician or gas supplier.
If the pilot will not stay lit after several tries,
turn the gas control knob to "OFF" and call
your service technician or gas supplier.
Natural Gas
PILOT GAS
BUTTON
GAS CONTROL
KNOB GAS CONTROL
KNOB
LP
PILOT
BURNER THERMO-
COUPLE
FOR YOUR SAFETY READ BEFORE LIGHTING
LIGHTING INSTRUCTIONS
TO TURN OFF GAS TO APPLIANCE
Set the thermostat to lowest setting.1.
Turn gas control knob clockwise to "OFF."2.
REPLACING THE GAS CONTROL
23079
The thermostat is designed with a single-use gas shutoff device. In the event that the gas shutoff
circuit is open, the control must be replaced. STOP! DO NOT ATTEMPT TO OPERATE THE
APPLIANCE. CALL A QUALIFIED SERVICE TECHNICIAN TO REPLACE THE GAS CONTROL.
Turn off all gas to the appliance and remove the gas line from the gas control.
With the gas control set to "OFF," turn on gas to the appliance. Check for leaks in the gas line and at
the main burner tube and pilot burner tube connection to the gas control. If a leak is detected, STOP!
Follow the safety instructions above on this label.
To put the appliance back into operation, follow the safety information and lighting instructions above
on this label.
Refill the appliance with water. See instruction manual for further information.
Install the new gas control into the tank (turn clockwise to tighten) and reconnect the
thermocouple, main burner tube, pilot burner tube and gas line to the gas control.
Remove the gas control from the tank (turn counterclockwise to loosen).
Loosen and remove the thermocouple, main burner tube, and pilot burner tube connection from the
bottom of the gas control.
Drain all water from the tank of the appliance. See instruction manual for further information.
Turn the gas control knob clockwise to "OFF."
1.
3.
9.
10.
8.
7.
6.
5.
4.
2.
Figure 5: Instructions To Put The Water Heater In O eration

Page 14 Atmospheric Gas
SECTION V: OPERATION (cont.)
IN PECT THE IN TALLATION AND ADJU T THE CONTROL
During the initial warm-up of the stored water, check for proper combustion by sampling
combustion gas at a point just below the exit of the flue. O2 readings should be in the range of
4.5-5.0% with CO levels at 0 ppm. Both combustion chamber access panels and insulation
(placed between panels) shall be installed when performing the combustion test. O2 readings
that greatly deviate from the specified range may lead to unsafe operating conditions. Factors
that can lead to O2 levels outside of the specified range include inadequate or excess draft
caused by ambient conditions or venting, obstructions underneath the water heater
preventing sufficient flow of air to burner, and improper inlet or manifold gas pressures. For
natural gas, the manifold pressure is preset at 4.0” w.c. and the acceptable inlet pressure is in
the range of 5-14” w.c. For propane gas, the manifold pressure is preset at 10.0” w.c. and the
acceptable inlet pressure is in the range of 11-14” w.c. See the “Pre-Installation” section of this
manual for information on clearances, air supply, and venting.
The thermostat has been adjusted to 120°F at the factory. Wait until thermostat has shut off
gas to the main burner. Wait 30 seconds following shut-off of gas, then set thermostat to the
highest temperature. The main burner should relight. Set thermostat to the lowest
temperature; the main burner should go out. The thermostat should be adjusted to the
minimum setting that will meet the hot water needs of the homeowner or commercial
application.
CAUTI N
There is a scald potential if the thermostat is set too high. The recommended temperature
setting for normal residential use is 120°F. If higher temperature settings are needed for
combined appliance applications or commercial use, an automatic tempering valve
must be installed on all domestic hot water lines.
MEA URING THE OUTCOMING WATER TEMPERATURE
The thermostat is factory set at 120°F for
domestic use. It is the responsibility of the
building owner to verify that the installer follows
the recommended quantitative testing for
measuring the outlet water temperature. To make
sure that the system works properly after installa-
tion and in the future, it is recommended that
the heater’s performance be measured and
monitored. Run water out of the tap nearest the
heater until it comes out warm. Using a
calibrated thermometer, take a measurement. If
the water is not at a suitable temperature for the
installation, have a qualified service person
adjust the temperature control. Contact Bock for
further information if needed.
This log (or a similar one) should be filled out as
follows:
䊱
!
Date Time Person running test Set temp °F utlet temp °F
Figure 6: A roximate Tem erature and
Dial Setting Relationshi

Atmospheric Gas Page 15
SECTION VI: MAINTENANCE
N TICE T THE WNER: If you are having a mechanical problem with your water heater,
contact your service company or installer.
WATER PIPING
On an annual basis, all piping should be checked for leakage at joints, shut-off valves, and
unions.
T&P RELIEF VALVE
On an annual basis, the temperature and pressure relief valve should be checked for proper
operation. First, attach a drain line to the valve to direct the water discharge to an open drain.
This is very important because the temperature of the discharge could be very hot. Second,
lift the lever at the end of the valve several times. The valve should operate freely and return
to its original position properly. If water does not flow out of the valve, remove and inspect
for corrosion or obstructions. Replace with a new valve if necessary. Do not repair the faulty
valve as this may cause improper operation.
ANODE ROD
Anode rods should be inspected twice in the first year and at least yearly once a time interval
for inspection has been developed. It is recommended to check the rod(s) six months after the
heater is installed. If the anode rod had reduced in size by two-thirds of its original diameter
of 3/4” or shows signs of pitting, it is time for replacement. Take the following steps when
changing the anode rod(s):
1. Shut off water supply.
2. Open any faucet to relieve tank pressure.
3. Remove caps on water heater top; push insulation aside.
4. Use a 1 1/16” six-sided socket wrench and a breaker bar. Snap hard to break the anode
rod seal.
5. Remove rod(s) and replace with new rod(s).
6. Turn water supply back on and leave faucet open until air is out of line.
7. Turn faucet off and check that new rod(s) doesn’t leak.
8. Snap caps back into place.
FLU H THE TANK
Elements in the water such as lime and iron may accumulate in the heater. Accumulation of
these elements can keep your water heater from operating at peak efficiency and may lead to
premature tank failure. It is recommended that the tank is drained and flushed thoroughly
once a year to prevent buildup.

Page 16 Atmospheric Gas
SECTION VI: MAINTENANCE (cont.)
IN PECT THE VENTING Y TEM
The vent system should be checked at least once a year for damage and blockage. A draft and
combustion test is also recommended.
If necessary, the water heater flue may be cleaned with a brush or flexible wire. Before
proceeding:
1) Turn the gas valve OFF.
2) Wait at least 5 minutes for the combustion chamber and flue to cool.
3) Use a brush or flexible wire to clean the flue. This can be done through the top of the flue.
It is not necessary to remove the burner.
4) Slide the brush down the flue at the base of each row of fins. This should knock any rust
flakes into the combustion chamber for removal.
WARNING
If the flue is blocked with soot this indicates serious combustion problems related to the
building and/or installation. These must be addressed before placing the water heater back
in operation.
5) Vacuum any sediment collected in the combustion chamber before restarting the heater.
Access to the combustion area can be obtained through the removal of the two access panels
and insulation. Be sure to replace all parts to their original positions prior to operating the
water heater.
SECTION VII: TRO BLESHOOTING
CAUTI N
For your safety, the repair and servicing of this equipment shall only be performed by a
qualified agency.
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!
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!
PPrroobblleemmPPoossssiibblleeccaauusseessRReeccoommmmeennddeeddAAccttiioonn
Cannot light pilot
5) Pilot tube leaking 5) Tighten connection at thermostat
1) Refer to lighting instructions1) Gas control knob not positioned correctly
2) Air in gas line 2) Purge gas line
3) Excessive water temperature and pilot failure. 3) Replace thermostat *
Water too hot or not hot enough 1) Thermostat set too high or low 1) Adjust setting as required
2) Thermostat out of calibration 2) Replace thermostat *
Insufficient hot water
Rumbling noise during burner
operation 1) Scale or sediment build-up in tank 1) Clean/flush tank
1) Heater undersized for load 1) Reduce hot water usage rate
2) Low gas pressure 2) Check gas supply and manifold pressure
2) Combustion air openings or flue/venting restricted 2) Inspect and clean.
3) Inadequate combustion/ventilation air to room 3) See "Pre-Installation" section
Poor combustion (sooting, CO)
4) Single use gas shut-off device opened in thermostat 4) Replace thermostat *
1) Accumulation of scale on burner 1) Turn OFF burner and clean
Pilot will not stay lit when gas
control knob or pilot gas button is
released.
2) Bad thermocouple 2) Replace thermocouple
3) Safety magnet breakdown 3) Replace thermostat *
1) Thermocouple connection is loose 1) Tighten connection at thermostat
3) Clogged pilot orifice 3) Clean or replace
4) Pinched pilot tube 4) Repair or replace
Table 3: Troubleshooting
* In the event that the gas thermostat needs to be replaced, contact a qualified agency to perform the replacement.

Atmospheric Gas Page 17
SECTION VIII: PARTS LIST
1
3
4
5
6
10
2
2
9
7
8
1 Hot Outlet Nipple 6 Gas Thermostat
2 Anode Rods 7 Inner Access Door
3 Draft Hood 8 Insulation
4 Dip Tube 9 Outer Access Door
5 T&P Relief Valve 10 Drain Valve
PPaarrttDDeessccrriippttiioonn
Figure 7: ezFIT Parts
Table 4: ezFIT Parts

Page 18 Atmospheric Gas
SECTION VIII: PARTS LIST (cont.)
2
6
3
5
4
2
1
1Burner
2 Pilot Kit
3 Main Burner Tube
4 Pilot Tube
5Thermocouple
6 Orifice (Natural or LP)
PPaarrttDDeessccrriippttiioonn
Figure 8: ezFIT Burner Parts
Table 5: ezFIT Burner Parts

Atmospheric Gas Page 19
SECTION IX: WARRANTY
LIMITED WARRANTY FOR GAS-FIRED WATER HEATER
Bock W ter He ters, Inc.
110 S. Dickinson Street
M dison, WI 53703
Phone: [phone]
WHAT DOES THIS LIMITED WARRANTY COVER?
This limited w rr nty pplies only to the origin l consumer purch ser.
Gener l Defects nd M lfunctions: This w rr nty covers defections nd m lfunctions in your
new w ter he ter for period of one ye r from the origin l inst ll tion d te. We will rep ir or
repl ce, t our option, ny defective or m lfunctioning component of the w ter he ter. This
limited w rr nty will termin te if you sell or otherwise tr nsfer the w ter he ter, or the w ter
he ter is inst lled t loc tion different from its origin l inst ll tion loc tion.
T nk nd He t Exch nger: We lso w rr nt th t the t nk nd he t exch nger will not le k due
to defective m teri ls or workm nship for five ye rs from the d te of origin l inst ll tion or
from d te of m nuf cture in the event the Limited W rr nty Registr tion C rd w s not
completed nd returned to m nuf cturer. If the t nk nd he t exch nger is le king nd we
h ve verified th t the le k is due to defect in m teri ls nd workm nship, we will repl ce
the t nk with t nk th t is the ne rest Bock model v il ble t the time of repl cement. If
repl cement t nk is provided, it will rem in w rr nted under this section s if it were the
origin l t nk. For ex mple, if we send you repl cement t nk under this limited w rr nty
two ye rs fter the origin l inst ll tion d te, then the repl cement t nk will rem in
w rr nted for the rem ining three ye rs fter the origin l inst ll tion d te.
HOW DO YOU GET SERVICE UNDER THE LIMITED WARRANTY?
In order for the w rr nty period to begin on the d te of inst ll tion, you must return the
w rr nty registr tion c rd tt ched below within 30 d ys of purch sing the w ter he ter. You
m y lso register your w ter he ter online t www.bockw terhe ters.com. You must h ve
copy of the origin l s les receipt t the time you request service. F ilure to return the w rr nty
registr tion c rd nd provide copy of the s les receipt will result in the w rr nty period
beginning from the d te of m nuf cture.
To get service under this limited w rr nty you should cont ct either the de ler or inst ller. If
de ler or inst ller is unknown you c n cont ct us vi e-m il t
w rr nty@bockw terhe ters.com or c ll us Mond y through Frid y between the hours of
8 o’clock .m. to 5 o’clock p.m. Centr l Time t the following number: 1-608-257-2225.
You c n lso write us t the following ddress:
Bock W ter He ters, Inc.
W rr nty Support Group
110 S. Dickinson Street
M dison, WI 53703
We will respond not l ter th n ten d ys fter we h ve received your request for service.

Page 20
SECTION IX: WARRANTY (cont.)
WHAT DOES THIS LIMITED WARRANTY NOT COVER?
This limited warranty does not over water heaters that are or were:
• In orre tly installed, espe ially where the installation violates state or lo al
plumbing, housing or building odes.
• Operated at inappropriate settings, ex essive pressures or temperatures.
• Exposed to adverse lo al onditions and spe ifi ally sediment or lime
pre ipitation in the tank or orrosive elements in the atmosphere or una eptable
water quality.
• Installed outside the United States or Canada.
• A identally damaged.
Also, we will not over the following harges, osts and losses:
• Any freight or delivery harges.
• Any removal or installation harges.
• Charges to return the water heater or part to the manufa turer.
• Water damage, loss or damage to property, in onvenien e or loss of use.
WHAT WILL VOID THE LIMITED WARRANTY?
If you do any of the following, you will void this limited warranty:
• Fail to retain an original opy of your sales re eipt.
• Fail to retain the a tual rating plate from the water heater.
• Alter or remove the serial number.
• Transfer or sell the water heater.
• Remove the water heater from its original lo ation and install it somewhere else.
• Fail to follow the are and maintenan e instru tions provided with the water
heater.
• Remove the anode rods.
• Fail to inspe t and repla e the anode rods (you must retain and present your paid
re eipts as proof of anode rod repla ement).
HOW DOES STATE LAW RELATE TO THIS LIMITED WARRANTY?
This is a limited warranty. WE MAKE NO OTHER EXPRESS WARRANTIES WITH RESPECT TO
THIS WATER HEATER. We will not assume, nor authorize any person to assume for us any
other liability in onne tion with the sale or operation of this water heater. ANY IMPLIED
WARRANTIES, INCLUDING MECHANTABILITY OR FITNESS FOR A PARTICULAR
APPLICATION, IMPOSED ON THIS SALE UNDER THE LAWS OF THE STATE OF SALE ARE
LIMITED TO ONE YEAR. This warranty gives you spe ifi legal rights, and you may also have
other rights whi h vary from state to state. Some states do not allow limitations on how long
an implied warranty lasts, so the above limitation may not apply to you.
WE WILL NOT BE RESPONSIBLE FOR WATER DAMAGE, LOSS OF USE OF THE UNIT,
INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL PROPERTY, WHETHER DIRECT OR
INDIRECT, AND WHETHER ARISING IN CONTACT OR TORT. Some states do not allow the
ex lusion of in idental or onsequential damages, so the above ex lusion may not apply to
you.
Bock Water Heaters, I c. • 110 South Dicki so Street • Madiso , WI 53703
Telepho e 608 -257-2225 • Fax [phone]
www.bockwaterheaters.com