State Water Heaters STC-080 How to use

SERVICE HANDBOOK
FOR
STANDARD RESIDENTIAL
GAS WATER HEATERS
(NON POWER VENTED MODELS)
Printed in the USA 0604 Part Number STC-080
$15.00
This service handbook addresses service issues associated with Standard Residential Gas
Water Heaters. Includes C-3 Flammable Vapor Technology.

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
1
TABLE OF CONTENTS
Page
Introduction
Terms.........................................................1
Tools..........................................................2
Residential Gas Water Heaters
Guidelines..................................................3
Installation..................................................5
Operations and Servicing
Construction...............................................6
Control.......................................................6
Burner........................................................7
Normal Operations ....................................7
Temperature..............................................8
Gas............................................................8
Water Flow.................................................9
Page
Service.....................................................10
Procedures and Conditions .....................11
Multiple Heater Piping..............................14
Exhaust Venting Notes ............................15
Flammable Vapor Ignition Design …….15
Lint, Dust & Oil Screen…………………16
Flame Arrestor…………………………..17
Thermal Cut Off Switch………………...18
Pilot Burner Assembly………………….19
Sealed Combustion Chamber…………20
Piezo Igniter……………………………..21
Technical Bulletins ……………….. 26
RESIDENTIAL GAS SERVICE HANDBOOK INTRODUCTION
This service handbook is designed to aid in servicing and troubleshooting State Non
Power Vented, Residential Gas water heaters in the field. No duplication or reproduction of this
book may be made without the express written authorization of the manufacturer.
The following text and illustrations will provide you with a step-by-step procedure to
verify proper installation, operation, and troubleshooting procedures. Additional quick reference
data is included to assist you in servicing this product.
The information contained in this handbook is designed to answer commonly faced
situations encountered in the operation of the Residential Gas, non power vented, product line
and is not meant to be all-inclusive. If you are experiencing a problem not covered in this
handbook, please contact the State Water Heater Call Center at 1-800-365-0024 or your local
State Water Heater Service Representative for further assistance. Additional information is also
available on the web site www.Statewaterheaters.com. This handbook contains supplemental
information to the Residential Gas installation instructional manual supplied with the water
heater.
Qualifications
This handbook is intended for use by licensed plumbing professionals and reference should be
made to the instructional manual accompanying the product.

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
2
Tools Required:
Phillips head screw driver
3/8, 7/16, ¾ inch open end wrenches
3/16 inch Allen wrench
11/16 inch – 6 point – socket – for anode removal
set of marked drill bits
electrical multimeter
gas pressure gauge or monometer
water pressure gauge
thermometer
tubing cutter if pilot tube is to be replaced
hose – to drain tank
container – to measure gallons per minute flow
MISCELLANEOUS INFORMATION
Draw efficiency is the quantity of hot water available to the consumer before the outlet water
temperature decreases 25 degrees F. A 40 gallon water heater will typically provide 70% (28
gallons) of this “usable” hot water. The burner is allowed to operate during this test. Incoming,
cold water mixes the remaining stored water below this 25 degree limitation.
Energy Factor is an indicator of the combined thermal efficiency and standby efficiency of a
water heater. The higher the energy factor, the more efficient the water heater will be.
Recovery rate is the amount of water that is heated to a set temperature, per hour. An
example might be that a water heater has a recovery rate of 30 gallons of water per hour at 80
degree F. (Fahrenheit) temperature rise.
“R” Value is a measure of the resistance of a substance to heat flow.
Thermal efficiency is approximately the amount of generated BTU (British Thermal Units),
which enters the water. A percentage of the total BTU passes out through the vent piping.
Temperature rise is the increase in the temperature from its coldest “inlet” water temperature
to the desired hot (outlet) setting. Typically this is assumed to be 40 degrees entering water;
120 degrees desired stored water or 80 degrees “temperature rise.”
Standby efficiency – the water heater’s ability to contain heat in the tank. A minimum of tank
water heat loss per hour is desired.
Sample: temperature change = Btu/h loss/ square foot of tank surface
“R” value
Water cannot (for all practical purposes) be compressed.
Water expands when it is heated.

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
3
Water Hammer – is a concussion of moving water against the sides of a containing pipe or
vessel on a sudden stoppage of flow.
EX: 1/2 “copper pipe, 5GPM flow (7.2ft/sec.) – stop. Pressure rise of approximately 412 PSI.
3/4” copper pipe, 5GPM flow (3.3ft/sec) – stop. Pressure rise of approximately 188 PSI
Minerals and gases will separate from water as temperature increases.
Formulas:
Btu (British Thermal Unit) is the heat required to raise 1 pound of water 1F
1 BTU = 252 cal = 0.252 kcal
1 cal = 4.187 Joules
BTU X 1.055 = Kilo Joules
BTU divided by 3,413 = Kilowatts
To convert from Fahrenheit to Centigrade: (° F – 32) times 5/9, or .556, equals degrees C.
One gallon of (120F, 49C) water weighs approximately 8.25 pounds.
Pounds X .45359 = Kilogram
Gallons X 3.7854 = Liters
% of Hot = (Mixed Temp. – Cold) divided by (Hot Temp. – Cold)
% Thermal Efficiency = (GPH X 8.25 X Temp. Rise X 1.0) divided by BTU/H Input
Btu Output = GPH X 8.25 X Temp. Rise X 1.0
GPH = (BTU/H Input X % Eff.) divided by (Temp. Rise X 8.25)
One cubic foot of Natural Gas contains about 1000 BTU of heat.
One “therm”is equal to 100,000 BTU
One cubic foot of Propane Gas contains about 2500 BTU of heat.
One gallon of Propane gas contains about 91,250 BTU of heat.
One pound of Propane gas contains about 21,600 BTU of heat.
One pound of gas pressure is equal to 27.7 inches water column pressure
Inches of Water Column X .036091 = PSI
Inches of Water Column X .073483 = Inches of Mercury (Hg.)

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
4
Centimeters = Inches X 2.54
MM (millimeters) = Inches X 25.4
Meters = Inches X .0254
Doubling the diameter of a pipe will increase its flow capacity (approximately) 5.3 times.
CONSTRUCTION:
Tank is constructed of steel.
The inside of the tank is constructed of a glass lining bonded to the steel. This prevents
water to metal contact and rusting of the tank.
An anode rod will be installed within the tank. The hex-head plug end of the anode is visible
on the top of the water heater. This metal rod offers secondary protection of the tank against
corrosion where the application of glass is not possible (threaded tank openings). These areas
will have small areas of water to metal contact.
All water heaters will contain at least one thermostat (to operate the heater) and one high
limit (to prevent water temperatures approaching the “steam” level).

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
5
INSTALLATION OF RESIDENTIAL GAS WATER HEATER
Exhaust Vent to
Outside of Building
Union
See Manual and
Labels For Installation
Clearances Temperature And
Pressure Relief
Valve – Do Not
Reuse Old Valve.
Expansion Tank
Pressurize to Equal
Supply Water
Pressure
Water
Shut Off
V
alve
Temperature and
pressure relief valve
tube piped to within 6”
of drain.
Thermostat –
recommended starting
point - 120F.
Safety Pan – Piped to
Drain
Drain
Inner and
Outer Doors –
Reinstall After
Lighting Pilot.
Air Is Drawn In For
Combustion. Keep
area clean and free
from flammables and
flammable vapors
Maximum Gas Supply
13.8” W.C. or ½ PSI
Minimum
4.5” W.C. –Natural Gas
11.0” W.C. Propane Gas
Installation Must Follow Local Codes and Instruction Manual Guidelines
Union
Typical Model
and Rating
Plate Location

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
6
RESIDENTAL GAS WATER HEATER SERVICE
This portion of this manual applies to the Operations and Servicing of Residential Gas, Tank
Type, Water Heaters, which are vented atmospherically and use a thermocouple as their
electrical source.
Control: There is one control on this style of water heater. The control has a main gas
regulator, pilot gas regulator, on-off-pilot knob, controls water temperature, has a temperature
adjustment knob, and a high water temperature limit safety.

(delta)
Note: The word “Hot”
may or may not be
present on the control
knob

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
7
Residential Gas – continued
Burner: The burner assembly consists of the main burner, main burner orifice, main burner
gas supply tube, pilot burner, pilot burner orifice, pilot burner gas supply tube and thermocouple.
The pilot burner remains on once it is manually lit. When incoming cold water activates the
thermostat, gas flows to the main burner. The pilot flame ignites this gas. The main flame
burns until the tank reaches set temperature then the thermostat interrupts this main gas flow.
AFTER HAVING CONFIRMED THAT THE WATER HEATER HAS BEEN INSTALLED
PER THE INSTALLATION MANUAL INSTRUCTIONS:
Normal Operation
Electrical: The Pilot Flame heats the end of a thermocouple. As the thermocouple is heated,
it generates a small (cannot be detected without an electrical meter) electrical current to the
bottom of the control valve. This current powers the electromagnet and holds open the safety
valve as long as the pilot flame is heating the thermocouple. DANGER! If the pilot is
extinguished, it can take up to 180 seconds for the thermocouple to cool sufficiently to close the
safety valve.
See also C3 technology product information beginning on page 15 .

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
8
Residential Gas – continued
Temperature: Two metal probes mounted
onto the back of the control are immersed
inside the tank water. One probe (the
shorter) acts as a temperature high limit. If
water gets excessively hot, a sensor within
the probe opens, interrupts the small
electrical current to the gas valve, and gas
flow through the control is interrupted. If this
safety sensor opens, the entire control must
be replaced.
The longer probe contains a metal rod that
expands and contracts as water temperature
around the probe cools and heats. As the
rod expands, it pushes against a lever
actuated gas valve. If the regulator is
pushed sufficiently, gas flow is interrupted to
the main burner. Adjusting the temperature
dial changes the distance the rod must
expand or contract to open or close the gas
valve.
Gas: When you prepare to light the pilot,
you are instructed to turn the top
knob to the pilot position and depress
the knob. When the knob is
depressed gas will flow to the pilot
burner only. You then have to
(manually) ignite this pilot gas. When
the pilot is lit, the flame must heat the
thermocouple until it generates
sufficient electricity to the gas valve
to allow you to release the knob while
gas continues to flow to the pilot.
When the top knob is turned to the
“ON” position, gas is also available to
the main burner if the thermostat calls
for heat.

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
State Water Heater Technical Training Department
© 2004 Ashland city, TN
9
Residential Gas - continued
Water Flow: When a hot water faucet is opened, water pressure from the well tank or street
main forces cold water into the water heater. This pushes hot water out of the tank.
Operation: A residential water heater is not a precise operating appliance. Because the water
heater relies on the expansion and contraction of a metal rod, when the thermostat dial is set at
an indicated setting (“▲” is recommended as a starting setting. This is approximately 120
degrees F.) The heater may shut off at 110 to 130F. The heater will consistently shut off at
this same temperature. For this same reason, water temperature may drop 15 - 25F, around
the temperature probe, before the main burner is activated. Keep in mind that hot water in the
upper part of the tank will probably be very near the “shut off” temperature of the control while
incoming cold water drops the water temperature around the thermostat probe. Also, short
repeating heating cycles caused by small hot water uses can cause temperatures at the point of
use to exceed the thermostat setting by up to 30° F.
Setting Approximate Temperature (°F) Time To Produce 2nd & 3rd
Degree Burns on Adult Skin
Hot (▲) 120° ± 10° 5 Minutes
A 130° ± 10° 30 Seconds
B 140° ± 10° 5 Seconds
C 150° ± 10° 1.5 Seconds
Very Hot 160° ± 10° Under 1 Second