A.O. Smith TC-049R3 Service Handbook
  1. Manuals
  2. Brands
  3. A.O. Smith Manuals
  4. Water Heater
  5. TC-049R3
  6. Service handbook
A.O. Smith TC-049R3 Service Handbook

A.O. Smith TC-049R3 Service Handbook

A.o. smith residential gas and electric water heater service handbook
Hide thumbs
Table of Contents

Advertisement

Quick Links

SERVICE HANDBOOK
Residential
Gas and Electric

Water Heaters

M O D E L S
C O V E R E D
Residential Gas Water Heaters that
are atmospherically vented and use a
thermocouple as their electrical source.
Residential Electric Water Heaters
having one or two heating elements
and common wiring configurations
for these models.
Part No. TC-049R3
• $15.00 • Printed in the U.S.A. • 0505

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the TC-049R3 and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for A.O. Smith TC-049R3

Summary of Contents for A.O. Smith TC-049R3

  • Page 1: Water Heaters

    Residential Electric Water Heaters having one or two heating elements and common wiring configurations for these models. Part No. TC-049R3 • $15.00 • Printed in the U.S.A. • 0505...

  • Page 2: Table Of Contents

    This service handbook is designed to aid in servicing and troubleshooting A.O. Smith Residential Gas and Electric water heaters in the field. No duplication or reproduction of this book may be made without the express written authorization of the A.O. Smith Water Products Company.

  • Page 3: Tools

    If you are experiencing a problem not covered in this handbook, please contact the A.O. Smith Technical Information Center at 1-800-527-1953 or your local A.O. Smith Water Products Company representative for further assistance. Additional information is also available on the web site www.aosmithwaterheaters.com.

  • Page 4: Terms

    BTU X 1.055 = Kilo Joules BTU divided by 3,413 = Kilowatts from Fahrenheit to Centigrade: (° F – 32) times 5/9, or .556, equals degrees C. To convert A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK = Btu/h loss/ square foot of tank surface is the heat required to raise 1 pound of water 1°F...
  • Page 5 All water heaters will contain at least (to prevent water temperatures approaching the “steam” level). limit A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK is constructed of steel. bonded to the steel. This prevents water...

  • Page 6: Installation

    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 A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Exhaust Vent to Outside of Building Union...

  • Page 7: Control

    There is one control on this style of water heater. The control has a main gas regulator, Contro pilot gas regulator, on-off-pilot knob, controls water temperature, has a temperature adjustment knob, and a high water temperature limit safety. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK σ(delta) Note: The word “Hot”...

  • Page 8: Normal Operations

    180 seconds for the thermocouple to cool sufficiently to close the safety valve. See also C3 technology product information beginning on page . A.O. Smith Water Products Company Technical Training Department Ashland City, TN...

  • Page 9: Temperature

    When the top knob is turned to the “ON” position, gas is also available to the main burner if the thermostat calls for heat. A.O. Smith Water Products Company Technical Training Department Ashland City, TN ©2005...

  • Page 10: Water Flow

    30° F. Setting Approximate Temperature (°F) Time To Cause Injury Hot (▲) Very Hot A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK 120° ± 10° 130° ± 10°...

  • Page 11: Service

    Pilot outage • Yellow burner flame • Sooting water heater • Possible carbon monoxide • Smell of burnt gas in the room A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK 1,000 Fuel (Enters Here) 12.5 Cubic Feet of Technical Training Department...
  • Page 12 W.C. from desired Additional considerations when pilot or main burner flames are too large or too small: • Incorrect orifice • Dirt in orifice or gas supply tubing A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Testing with Pressure Gauge is measured using the Allen wrench tap on the bottom …...

  • Page 13: Procedures And Conditions

    Light the pilot and continue to hold this knob down while conducting the test. If … reading test of at least 13 MV is not present reading test of at least 13 MV is present A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then check for lack of supply air.
  • Page 14 Increased combustion efficiency – higher thermal efficiency means that an increased amount of heat is transferring from the flue gas into the water. If you transfer (approximately) 87.5%, or more, the moisture in the flue gas will condense. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK …...
  • Page 15 If … any of the above conditions exist Suggested Multiple Heater Water Piping Required For Proper Operation of Top Connect Models A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then raise the supply air temperature or •...

  • Page 16: Exhaust Venting Notes

    United States with BTU ratings of 75,000 or less are required to meet this new ANSI standard effective July 1,2003. The current implementation schedule for C3 TECHNOLOGY compliant residential gas-fired products is shown in the following table. These dates are subject to change. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK “D”...
  • Page 17 Pilot outage resulting from a lack of oxygen • Pilot outage resulting from to increased combustion chamber temperature below the main burner. This may open the automatic reset, thermal cut off switch (TCO). A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK CLASS OF PRODUCTS INCLUDED IN THIS CATEGORY 30, 40, and 50 gallon atmospheric vented.

  • Page 18: Flame Arrestor

    Inspect with the mirror and flashlight. Vacuum or blow down any blocking material. If you blow down through the ports, be certain to also vacuum below the arrestor. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...

  • Page 19: Thermal Cut Off Switch

    There is no routine service associated with the TCO. The standard thermocouple millivolt output checks described in this service handbook still apply. Millivolt readings indicate that the TCO is closed. An open TCO (within a cool chamber) would indicate that the assembly must be replaced. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...

  • Page 20: Pilot Burner Assembly

    1. Thermocouple with integral Thermal Cut Off switch (TCO). 2. Pilot burner w/orifice and tubing 3. Piezo igniter cable 4. Pilot assembly seal/grommet (orange). 5. An inner door gasket (white) will also be included. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Technical Training Department Ashland City, TN...

  • Page 21: Sealed Combustion Chamber

    The pilot tube and thermocouple routing should be straight (not bent at an angle close to the surface of the seal) as it passes through the pilot assembly seal. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...

  • Page 22: Company

    The push button switch will be located on the top of the gas control valve. There will be a plug connector between the push button and the igniter wire which is part of the pilot burner assembly. A.O. Smith Water Products Company ©2005...

  • Page 23: A.o. Smith Water Products Company

    (the CSA symbol). A sample might be: Model “PCVG-50 – 250” “Ser No. MB03-(numbers) – 250”. To order parts, contact your local A.O. Smith Contractor or Distributor, phone AOS parts at 800-433-2545 or contact A. O. Smith on Web site: “www.aosmithwaterheaters.com”...

  • Page 24: Installation

    RATING PLATE WITH MODEL AND SERIAL NUMBER SEE MANUAL AND LABELS INSTALLATION CLEARANCES INSTALLATION MUST FOLLOW LOCAL CODES AND INSTRUCTION MANUAL GUIDELINES. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK INSTALLATION TO †FUSED ELECTRICAL SUPPLY (BREAKER BOX) UNION COLD WATER...
  • Page 25 Tank Type, Water Heaters. The illustrations are for two element models but the information also applies to single element models. Multiple Heater Water Piping Required for Proper Operation of Top Connect Models TEMPERATURE/PRESSURE RELIEF VALVES A.O. Smith Water Products Company Technical Training Department Ashland City, TN ©2005...

  • Page 26: Guidelines

    (If they operate at the same time, amperage draw doubles, wire gauge size increases, fuse size increases and little is gained in heat recovery.) A.O. Smith Water Products Company Technical Training Department Ashland City, TN...
  • Page 27 • Voltage Notes: 120 volt AC circuit (Hot) L1 to Ground = 120 Volts L2 to Ground = 0 Volts A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK (Hot) L1 or L2 to Ground = 120 Volts L1 L2 = 240 Volts...
  • Page 28 Older 59T controls had a maximum setting of 170°F. Replacement 59T controls will stop at 150°F. 89T controls are combination High Limit/Thermostat, one piece controls. 66T limits may be mounted onto 59T thermostats. 66T4400 59T4100 A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Newer Older Models Models...

  • Page 29: C-2 Circuit

    C-2 Circuit • Single element • Single thermostat • Single High Limit A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK C-2 Circuit Prior to 1996 Power Enters High Limit 1 and 3 Through High Limit 1, 2 and 3, 4...

  • Page 30: Thermostat

    L1 to T2 and L3 to L4 Thermostat T2 Contacts T2 Contacts Closed Open A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Note: If used on a normally two element heater, controls will be located behind the upper service cover and the element behind the lower service cover.

  • Page 31: A-6 Circuit

    Power Enters High-Limit Through High Limit 1, 4 Contacts Open Power Interrupted to Upper Element Upper Thermostat, 1, 2 Open A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK A-6 CIRCUIT Upper Thermostat 1, 2 Contacts Closed Power to Upper Element...

  • Page 32: Wiring Diagram

    Operation: From cold tank of water Power Enters High-Limit Through High Limit Upper Thermostat Contacts Open Power Interrupted to Upper Element Open A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK A-6 Circuit - Post 1995 Contacts Closed Power to Upper /Element Element Heats Water...

  • Page 33: A-7 Circuit

    “Off Peak” meter, which interrupts power to the lower element during the time of day when electricity is more expensive. This customer relies on additional hot water storage to meet their needs while this element is off. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...
  • Page 34 To Lower High Limit 1. Lower High Limit 1, 2 Is Closed Lower Thermostat 1, 2 Is Closed Lower Element Heats Bottom 2/3 Of Tank A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK A-7 Circuit Prior to 1996 Fused Disconnect...
  • Page 35 2 High Limits • 4 Wire Four wire circuit for non-simultaneous element operation. This circuit permits off-peak meter usage and connection to 3 phase supply circuit. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK WIRING DIAGRAM A-7 – Post 1995 *Interrupts power to lower element during “peak”...
  • Page 36 Upper Thermostat 3, 4 Closes Power Flows Between Upper Thermostat 4 and Lower High Limit L1 Lower High Limit L1 and Lower Thermostat T2 is Closed A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK A-7 Circuit Post 1995 Fused Disconnect...

  • Page 37: Certification And Approvals

    The following paragraph describes the relationship between ASHRAE, NAECA and the Department of Energy’s ENERGY FACTOR as it relates to the residential electric product lime. All of the A.O. Smith residential electric water heaters meet this code. The American Society of Heating, Refrigeration and Air Conditioning Engineer (ASHRAE) guidelines follow the National Appliance Energy Conservationist Act (NAECA).
  • Page 38 Note: Residential heaters may or may not offer the ability to wire elements for simultaneous operation. If they are wired for non-simultaneous operation, amperage will be as if wired single phase. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK 3 Supply Wires...

  • Page 39: Ohms Check

    (+7.5%) is present meter reads "0" meter reads "1" or off scale ** The above test can also be conducted with the element removed from the tank. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK SERVICE … then continue testing.
  • Page 40 Test voltage between 4 and 2 or T2 and L4 If … rated voltage is not present rated voltage is present A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Voltage Checks … then check circuit breaker (fused disconnect) •...
  • Page 41 Test between 4 and 2 or L4 and T2 If … rated voltage is present lower than rated voltage is present no voltage is present A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then check wiring from control. repeat Ohms resistance test of element •...
  • Page 42 59T4000 Test around red wire then black wire to element. If … amperage is noted (indicating flowing power) amperage is not noted A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK must push the high limit reset … then replace the element.

  • Page 43: Ohms Check

    (+7.5%) is present meter reads "0" meter reads "1" or off scale ** The above test can also be conducted with the element removed from the tank. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK A-6 Circuit Servicing … then continue testing.
  • Page 44 NOT present Test between 2 and 4 or L1 and L4 If … correct supply voltage is present correct supply voltage is NOT present, still no power A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Voltage Check … then continue.
  • Page 45 Test between high limit 4 and lower thermostat 2 or L4 and 2 If … correct supply voltage is present correct supply voltage is not present A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then continue.

  • Page 46: Grounded Element Test

    (+5, - 10%) meter reads approximately ½ of the proper amperage meter reads NO amperage A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Amperage Method - using “clamp type” Amperage – must push the high limit reset …...
  • Page 47 If the consumer uses enough of the stored hot water to drop tank temperature at the top of the tank to call for upper element activation, then the upper element will reheat the upper third of the tank A.O. Smith Water Products Company Technical Training Department Ashland City, TN...

  • Page 48: A-7 Service

    (+7.5%) is present meter reads “0” meter reads “1” or off scale ** The above test can also be conducted with the element removed from the tank. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then continue testing.

  • Page 49: Voltage Checks

    Test between upper high limit 4 and upper thermostat 2 If … the proper voltage is not present high limit and upper thermostats 2 the proper voltage is present A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Voltage Checks … then check power from the breaker (fused disconnect).
  • Page 50 Test between lower high limit 2 and 4 or L1 and L4 If … proper voltage is not present pushing reset restored voltage pushing reset did not restore voltage proper voltage is present A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then replace upper thermostat. continue to next step.
  • Page 51 Test between the terminals of the lower element If … proper voltage is not present: proper voltage is present: A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then check jumper between lower high limit •...
  • Page 52 ½ of the proper amperage meter reads NO amperage Note: Amperage will only be indicated while electricity flows through a wire. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK … then the thermostat is calling for heat...
  • Page 53 57.7 92.8 74.3 Rated Voltage 3000 3500 4.64 14.4 12.4 18.6 15.9 25.6 21.9 76.8 65.7 A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK Element with Links Rated Wattage 1000 1250 1500 13.9 11.1 9.28 43.3 34.6 28.8 55.7 44.6 37.1...

  • Page 54: Technical Bulletins

    Chlorination Procedure... 61 Not Enough Hot Water - Gas ... 62 Not Enough Hot Water – Electric ... 63 Thermal Expansion…………………………………………………...64-65 Leaking Temperature and Pressure Relief Valve... 66 A.O. Smith Water Products Company Technical Training Department Ashland City, TN ©2005...
  • Page 55 Mineral buildup in some heaters prevents them leaking while greatly reducing efficiency. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK A Temperature and Pressure Relief Valve limits pressure to a maximum.
  • Page 56 For more detailed explanation on this information as well as additional service information, see the A.O. Smith Web site www.hotwater.com 0801 form TC-063 A.O. Smith Water Products Company ©2005...

  • Page 57: Technical Bulletins

    Arrestors should be located as close as possible to the source of the shock wave. Since water hammer exposes the equipment to pressures in excess of its design NOTES limits, failures caused by water hammer are not eligible for warranty consideration. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN...

  • Page 58: Mineral Buildup

    The most commonly used is phosphoric acid at a food-grade level. Two common treatments marketed by A.O. Smith are Mag-Erad® and Un- Lime®. Any well-stocked plumbing supply house should have a deliming solution available.

  • Page 59: Aluminum Hydroxide

    On electric models, return the wiring to its original configuration. Turn heater fuel “ON”. Since aluminum hydroxide is a product of a chemical reaction dependent on the water condition, NOTE any treatment is not considered warranty related. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN BULLETIN 14 ALUMINUM HYDROXIDE GAS - Heat for 7 to 10 minutes.

  • Page 60: Discolored Water

    See Bulletin 23 for the chlorination procedure. Since rusty water is caused by a bacteria presence and is not caused by the NOTE water heater, any treatment would not be considered warranty related. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN...

  • Page 61: Smelly Water

    Since smelly water is caused by a bacteria presence and is not caused by the NOTE water heater, any treatment would not be considered warranty related. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN...

  • Page 62: Chlorination Procedure

    Return hot water heating system to service by following the recommended STEP 13 start-up procedure posted on the unit or in the manual. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN BULLETIN 23...

  • Page 63: Not Enough Hot Water - Gas

    STEP 9 Step 6 - if the temperature was not within range, check the thermostat. THE FIX Step 9 - if more than 30 °F was lost, check the dip tube. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN...

  • Page 64: Not Enough Hot Water - Electric

    Step 6 - if the temperature was not within range, check the thermostats. THE FIX Step 9 - if more than 30 °F was lost, check the lower element for continuity and the dip tube. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK TECHNICAL BULLETIN...

  • Page 65: Thermal Expansion

    The temperature and pressure relief valve (T&P) or PRV should open and release water once the pressure reaches the maximum setting on the valve. The valve will close once the pressure falls below the pressure setting of the valve. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...
  • Page 66 These failures are not covered by the manufacturer’s warranty, so it is extremely important that everyone be aware of the causes, symptoms and solutions to thermal expansion in a closed water heating system. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...

  • Page 67: Leaking Temperature And Pressure Relief Valve

    Large volume of hot water sporadically discharged from the relief valve - The relief valve relieves water quickly when actuating on temperature. The only cause of this problem is a malfunctioning thermostat. A.O. Smith Water Products Company ©2005 SERVICE HANDBOOK...
  • Page 68 ____ Other ______________________________ Additional comments or suggestions to improve this service handbook: Please cut out this page and return your comments to: Technical Training Department - FAX 1-615-792-2135 A.O. Smith Water Products Company Technical Training Department Ashland City, TN ©2005...

Table of Contents