State Industries STC-074 User Manual
SBN 71120 through 85390 (A)
SERIES 100 Models
SBN Meets Low NOx Requirements of SCAQMD
Rules 1121 & 1146.2
Service
Handbook
For Self-Cleaning
Induced Draft
Multi Flue Commercial
Gas Water Heaters
Part No. STC-074
For propane inputs and other more detailed information,
$20.00 Printed in the U.S.A. 0204
visit www.statewaterheaters.com to view or download Specification Sheets.
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
TABLE OF CONTENTS
SBN Service Handbook Introduction ................................................2-3
Installation Considerations ...................................................................4
Clearances .......................................................................................4
Exterior Clearance............................................................................ 5
Air Supply .........................................................................................6
Contaminated Air.............................................................................. 9
Flammable Items .............................................................................. 9
Gas Valve ....................................................................................... 10
Outlet View ..................................................................................... 11
Venting ........................................................................................... 12
Technical Data Venting ..............................................................13-14
Sequence of Operation........................................................................15
Top View .........................................................................................15
Front View....................................................................................... 16
White Rogers Control .....................................................................17
HSI Board .......................................................................................18
Wiring Diagram............................................................................... 20
Electrical Sequence .......................................................................21
Pre-Service Checklist...........................................................................22
Control Board Diagnostic LED Interpretation and Troubleshooting
120 VAC Check to Heater ...............................................................23
Polarity Check ................................................................................ 24
Continuity Check of High Limit ....................................................... 25
Upper Temperature Probe Check ................................................... 26
Inducer Check ................................................................................ 27
Blower Prover/Low Gas Pressure Circuit Check ............................ 28
HSI Voltage and Continuity Check ................................................. 29
Igniter and Gas Valve Circuit Check ...............................................30
Gas Valve Coil Continuity Check.................................................... 31
Flame Prover Check ....................................................................... 32
Water Temperature Circuit Check ................................................... 33
Technical Training Department ©2003
Ashland City, Tennessee
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
TABLE OF CONTENTS
Troubleshooting - Conditions .............................................................34
LED Troubleshooting...........................................................................36
Parts List ...............................................................................................38
General Questions and Answers ........................................................ 41
Electrical Information ...........................................................................44
Draft Proving (Pressure) Switch T able................................................44
SB
N Service Handbook Introduction
This service handbook is a supplement to the SBN Installation and Operation Manual.
The handbook provides information on servicing and troubleshooting State Industries
SBN water heaters in the field. While this handbook is not intended to be all inclusive, it
contains:
• step-by-step procedures with illustrations to verify proper installation, operation,
and troubleshooting
• quick reference data to assist in servicing the product line
• answers to common questions encountered in the operation of the product
line
The handbook is intended to be used by licensed plumbing professionals. Reference
should be made to the installation manual accompanying the product. If you are
experiencing a problem not covered in this handbook, please contact the State
Industries Technical Information Department at 1-800-527-1953 or your local State
Industries representative for further assistance.
No duplication or reproduction of this book may be made without the expressed
written authorization of the State Industries.
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
Qualifications
Installation or service of this water heater requires ability equivalent to that of a
licensed tradesman in the field involved. Plumbing, air supply, venting, gas supply and
electrical testing skills are required.
Tools Required
• Phillips head screwdriver
• standard screwdrivers
• 3/8 and 7/16 inch open end wrench
• set of marked drill bits
• electrical multimeter tester capable of measuring continuity, AC voltage and DC
voltage
• gas pressure gauge or manometer (gauge - pt. no. 8099-2)
• water pressure gauge (pt. no. 4798)
• thermometer (pt no. 4870 - range 0 - 220 degrees F)
• 1/2 inch socket with extension for removal of the clean out cover
• 1-1/16 inch socket with extension for anode removal
Custom Commercial Storage Tank Model Number Break Down
U G V 66 01500 V A
V = Vertical
H = Horizontal
100# or 125# or 150# or 160#
A = ASME
U = Unjacketed
J = Jacketed
G = Glass-Lined
E= Epoxy
B = Black Steel
C + Cement
V = 5 Year
Warranty
Gallon Capacity
Diameter
SPECIAL NOTE: All model number appearing on rating plate and carton labels will
be compressed. Example: UGV6601500VA125
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1 2 5
ASME Pressure Rating =
SBN TANK TYPE COMMERCIAL GAS WATER HEATER
g
SERVICE HANDBOOK
INSTALLATION CONSIDERATIONS
This portion of the handbook reviews some often overlooked installation considerations
—clearances, air supply, gas pressure requirements, and venting—taking note
of necessary installation requirements for SBN . The installation manual
covers most of these items in detail.
Clearances
A 24-inch clearance for all serviceable parts is recommended. Clearances may vary
between models. See instruction manual or the label on the heater for clearances
applicable to your specific model.
Top and Front Views of Minimum Clearances To Combustibles
Minimum Clearances To Combustibles
Model "A" Right
Side
SBN 71-120NE, SBN- 81-154NE, SBN 81-180NE, SBN 100-199NE 2" 2" 2" 12"
SBN 100-250NE(A), SBN 100-275NE(A), SBN 85-310NE(A) 3" 3" 3" 12"
SBN 85-366NE(A) 6" 6" 6" 6"
SBN 85-390NE(A) 4" 4" 4" 4"
"B" Left Side "C" Back "D"
Ceilin
A, B, and C clearances to non-combustibles is “0” inches - a 12 inch clearance to cover
remains unchanged.
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
Exterior Clearance
The illustration below shows the required clearances for venting units using
natural draft venting.
Required Exterior Clearances
“Copyright by the American Gas Association. Used by permission of the copyright holder”.
The vent must extend at least 3 feet above the highest point where it passes through
a roof of a building and at least 2 feet higher than any portion of a building within a
horizontal distance of 10 feet (for vents of 12 inches in diameter or less).
References: NFPA 54 ANSI Z 223.1 SEC 7.5.2a and Sec 7.6.2a may allow reduction
to 8 feet with a “listed vent cap.”
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
Air Supply
Stoichiometric or theoretical complete combustion requires 10 cubic feet of air per
1,000 BTUH of gas supplied. The National Fuel Gas code also recommends an
additional 2.5 cubic feet of “excess” air.
For information on minimum make-up air opening sizes for various building installations,
refer to the National Fuel Gas Code NFPA 54, ANSI Z223.1, Sec. 5.3.
10 CU.
FT.
COMB.
1,000
BTU
AIR
2.5 CU.
FT.
EXCESS
AIR
Insufficient make-up air is a major cause of combustion problems.
Insufficient Make-Up Air - Backdraft
One common example is in a restaurant installation where exhaust vent equipment was
not considered in sizing make-up requirements. This condition may result in air being
backdrafted by the restaurant exhaust equipment through the heater causing the draft
proving switch to open and/or erratic heater shutdown.
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Technical Training Department
Ashland City, Tennessee
SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
A fresh supply of make-up air for combustion can be supplied to the heater through
make-up air ducts, which directly communicate with the outdoors.
Make-Up Air – Direct Communication
(Not Direct Vent)
Two openings are required: one within 12 inches of the top of the enclosure and one
within 12 inches of the bottom of the enclosure. Each opening must have a free area
of not less than 1 square inch per 4,000 BTUH of the total input of all appliances
within the enclosure.
The lower opening primarily provides combustion air. The upper opening provides
vent dilution air and acts as a relief opening for flue gases should the vent become
obstructed or a downdraft condition occur. Additionally, when the heater is installed in
a confined space and communicating with the outdoor air, one permanent opening,
beginning within 12 inches (30 cm) of the top of the enclosure, must be permitted
where the equipment has clearances of at least 1 inch (2.5 cm) from the sides and
back, and 6 inches (16 cm) from the front of the appliance. The opening must directly
communicate with the outdoors and must communicate through a vertical or
horizontal duct to the outdoors or spaces (crawl or attic) that freely communicate with
the outdoors, and must have a minimum free area of a) 1 square inch per 3,000 BTUH
(7cm2 per kW) of the total input of all equipment located in the enclosure and b) not
less than the sum of the areas of all vent connectors in the confined space.
Technical Training Department ©2003
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
Often, it is more practical to install vertical make-up ducts to the outdoors.
Make-Up Air - Vertical Ducts
Again, two openings are required: one within 12 inches of the top of the enclosure
and one within twelve inches of the bottom of the enclosure. Each opening must
have a free area of not less than 1 square inch per 4,000 BTUH of the total input of
all appliances within the enclosure.
Make-Up Air - Horizontal Ducts
When the heater is installed in an interior room with no roof access for vertical ducts,
horizontal make-up air ducts should be installed. When using horizontal ducts, two
openings are required - one within 12 inches of the top of the enclosure and one within
12 inches of the bottom of the enclosure. Each opening must have a free area of not
less than 1 square inch per 2,000 BTUH of the total input of all appliances within the
enclosure.
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Technical Training Department
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
Along with adequate make-up air, the quality of the air is important.
Contaminated Air
RustRust
Rust
RustRust
ChipsChips
Chips
ChipsChips
Contaminants in combustion air can lead to premature heater failure. Vapors from
bleaches, soaps, waxes, salts, etc. are drawn into the combustion chamber with the
make-up air and, once fired, mix with water vapor in the gases to form extremely
corrosive hydrochloric or hydrofluoric acid and other corrosive by-products.
Air for Combustion – Flammable Items
Flammable items, pressurized containers or any other potentially hazardous articles
must never be placed on or adjacent to the heater. Open containers of flammable
material should not be stored or used in the same room with the heater.
Technical Training Department ©2003
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
The supply gas pressure is
normally measured at the gas
valve inlet gas pressure tap,
if available, when the gas is flowing.
The manifold gas pressure
is measured at the manifold
pressure tap of the gas valve
when the gas is flowing.
Gas valves used are 24 volt AC
combination-step opening gas
valves. They incorporate the
main valve and gas pressure
regulator into one body. The
Low Gas Pressure Switch, the
Supply Gas Inlet, and the
Supply Gas Pressure Tap are
shown in the Inlet View to the
right.
Gas Valve
Inlet View
Top View
The top view of the gas valve,
shown on the right, shows the
Main Gas Regulator, Manifold
Pressure Tap, Top Knob, and the
Limited Bleed Vent Port. The main
gas regulator is found under the
silver cap screw. It is factory preset
to 3.5 inches W.C. and
adjusts gas pressure output
from 3.0 to 5 inches water
column. Caution: Always test
the manifold pressure at the
outlet when the gas is flowing.
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Technical Training Department
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
The outlet view of the Gas
Valve, shown on the right,
shows the Manifold Gas
Outlet Connection, the two
24 volt Main Valve (MV)
Solenoid connections, and
the Manifold Pressure Tap.
The two yellow wires from
the 12-pin plug on the
Ignition Board attach to the
MV terminals.
SERVICE HANDBOOK
Outlet View
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SERVICE HANDBOOK
Venting
All SBN water heaters are classified by ANSI as Category I (non-condensing,
negative pressure venting) appliances. They are approved for type B vent. The draft
inducer does not pressurize the exhaust.
Venting – Atmospheric Multiple Heaters
For larger applications, SBN water heaters can be common vented together,
either in a tapered manifold or constant size manifold. Follow the National Fuel Gas
Codes requirements for sizing and installation of fan-assisted products.
SBN Models may be common vented only with other Category I appliances. See the
Venting Section in the National Fuel Gas Code.
©2003
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
A
A
SERVICE HANDBOOK
When vents are combined, the area of the combined vent should be equal to area of the largewst
single vent, plus 50% of area of all others joining.
EXAMPLE: To combine two 6” vents with
an 8” vent, the area of a
combined vent should be
one half area of two 6 inch
vents (14 + 14) plus area of 8 inch vent (50)
or 78 sq. inches. Referring to char, 78
sq. inches require 10” diameter vent.
NINE RULES FOR
GOOD VENTS
rea in
Vent Size
5" 20 10" 79
6" 28 12" 113
7" 38 14" 154
8" 50 16" 201
9" 64 18" 254
Square Inches Vent Si ze
rea in
Square Inches
1. The vent pipe should ALWAYS
be the same size as the outlet of
the draft diverter or factory
supplied vent reducer.
• Model SBN 120 are
supplied with a 6” to 5”
reducer.
• Models SBD 250, 251
and 275 are supplied
with a 8” to 6” reducer.
2. The diameter of a vent pipe
should NEVER be reduced, no
matter what the circumstances.
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SBN TANK TYPE COMMERCIAL GAS WATER HEATER
3. In some cases it may be
necessary to run a vent larger
than the draft diverter outlet.
SERVICE HANDBOOK
4. Take the maximum vertical
rise possible immediately
above the draft diverter.
5.
©2003
6. Horizontal pipe should be sloped
upward at a minimum of ¼” per foot.
7. Horizontal elements should be limited to
75% of the vertical rise of the vent above
the connection.
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