State Industries STC-080 User Manual

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

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

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 “R” value

Water cannot

(for all practical purposes) be compressed.

Water expands when it is heated.

= Btu/h loss/ square foot of tank surface

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER

SERVICE HANDBOOK

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

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.)

of Propane gas contains about 21,600 BTU of heat.

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER

SERVICE HANDBOOK

Centimeters = Inches X 2.54 MM (millimeters) = Inches X 25.4 Meters

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 water to metal contact and rusting of the tank.

An 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

limit (to prevent water temperatures approaching the “steam” level).

= Inches X .0254

glass lining bonded to the steel. This prevents

anode rod will be installed within the tank. The hex-head plug end of the anode is visible

one thermostat (to operate the heater) and one high

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER

INSTALLATION OF RESIDENTIAL GAS WATER HEATER

See Manual and Labels For Installation Clearances

Typical Model and Rating Plate Location

Union

SERVICE HANDBOOK

Exhaust Vent to

Outside of Building

Union

Water

Shut Off

alve

Expansion Tank Pressurize to Equal Supply Water Pressure

Temperature And Pressure Relief Valve – Do Not Reuse Old Valve.

Maximum Gas Supply

13.8” W.C. or ½ PSI Minimum

4.5” W.C. –Natural Gas

11.0” W.C. Propane Gas

Air Is Drawn In For Combustion. Keep area clean and free from flammables and flammable vapors

Installation Must Follow Local Codes and Instruction Manual Guidelines

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.

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER



SERVICE HANDBOOK

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

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

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

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 (▲)

A 130° ± 10° 30 Seconds B 140° ± 10° 5 Seconds C 150° ± 10° 1.5 Seconds

Very Hot 160° ± 10° Under 1 Second

120° ± 10° 5 Minutes

RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER

SERVICE HANDBOOK

Residential Gas - continued

Service:

A gas burning appliance requires the oxygen contained in 12.5 cubic feet of air (at sea

Air:

level) for every 1000 BTU of heat that is generated. If your water heater has a BTU per hour input of 40,000 BTU then a minimum of 500 (40 times 12.5) cubic feet of clean air must be available. This oxygen will mix with the gas for a clean, blue flame in the burner chamber and provide dilution air for flue products.

(Enters Here)

1,000

BTU Fuel

12.5

Cubic

Feet of

Air

(Enters Here)

Do not forget that your gas (or oil) furnace and gas clothes dryer also require a like amount of air.

When calculating air supply provisions, also consider the presence of whole house exhaust fans or other exhaust fans competing for the same air supply.

Air must be allowed to enter the heater chamber from the base of the heater and also enter the flue vent from below the draft hood. Do not block these areas with insulation blankets or obstructions lying around the base of the heater.

Lack of Oxygen: If a sufficient supply of oxygen (air) is not available for combustion and

dilution, the result will be:

 Pilot outage  Yellow burner flame  Sooting water heater

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