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A.O. Smith 12 40GPC T 100 Service Handbook

Standard residential high efficiency atmospheric vent (fvir) gas water heaters
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SERVICE HANDBOOK FOR
HIGH EFFICIENCY ATMOSPHERIC VENT
(FVIR) GAS WATER HEATERS
MODELS:
GAHH 40 100,
GP 6 40YPC T 100,
PCG6240T403NOV 100,
PCG2J4040T3NOV 100,
12 40GPC T 100,
PCG2J4040T3NOV 100,
Printed in U.S.A. 10/10
STANDARD RESIDENTIAL
GAHH 50 100,
GP 6 50YPC T 100,
PCG250T403NOV 100,
PCG2J5040T3NOV 100,
12 50GPC T 100,
PCG2J5040T3NOV 100
1
318181-000

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Summary of Contents for A.O. Smith 12 40GPC T 100

  • Page 1 HIGH EFFICIENCY ATMOSPHERIC VENT (FVIR) GAS WATER HEATERS MODELS: GAHH 40 100, GP 6 40YPC T 100, PCG6240T403NOV 100, PCG2J4040T3NOV 100, 12 40GPC T 100, PCG2J4040T3NOV 100, Printed in U.S.A. 10/10 GAHH 50 100, GP 6 50YPC T 100, PCG250T403NOV 100, PCG2J5040T3NOV 100,...
  • Page 2 ALL TECHNICAL AND WARRANTY QUESTIONS SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED. IF YOU ARE UNSUCCESSFUL, CONTACT A. O. SMITH WATER HEATERS RESIDENTIAL TECHNICAL ASSISTANCE AT 1-800-527-1953 OR WWW.HOTWATER.COM.

  • Page 3: Introduction: Service Handbook Introduction

    Your safety and the safety of others is extremely important in the servicing of this water heater. Many safety-related messages and instructions have been provided in this handbook and on the water heater to warn you and others of a potential hazard. Read and obey all safety messages and instructions throughout this handbook.

  • Page 4: Warnings And Cautions

    Fire or Explosion Harzard Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. Avoid all ignition sources if you smell Natural or LP gas. Do not expose water heater control to excessive gas pressure.

  • Page 5: Table Of Contents

    INTRODUCTION: Service Handbook Introduction ...3 Warnings and Cautions ...4 Table Of Contents ...5 INSTALLATION / OPERATION: Basic Installation & Operation ...6 Combustion Air and Vent System Requirements ... 7-10 KNOW YOUR WATER HEATER: Know the Water Heater’s Component Parts ...11-13 Water Heater Operation ...14 Filling and Draining the Water Heater ...15 Lighting Instructions ...16...

  • Page 6: Basic Installation & Operation

    BASIC INSTALLATION & OPERATION INSTALLATION OF RESIDENTIAL GAS WATER HEATER See Labels and Installation Instructions and Use & Care Guide for clearances. Use Draft Hood supplied with unit Union To Fixtures - Hot Tempered Water To Fixtures Untempered Cold Hot Water Water Inlet Water...

  • Page 7: Combustion Air And Vent System Requirements

    COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS Combustion Air Requirements: WARNING Carbon Monoxide Warning Water heater must be vented to outdoors. Vent must be installed by a qualified technician using the local and state codes or, in the absence of local and state codes, the National Fuel Gas Code, ANSI Z223.1 (NFPA 54) - current edition, and/or the installation instructions.
  • Page 8 COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS All Air from Inside the Building: When additional air is to be provided to the confi ned area from additional room(s) within the building, the total volume of the room(s) must be of suffi cient size to properly provide the necessary amount of fresh air to the water heater and other gas utilization equipment in the area.
  • Page 9 COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS 1 SQ. INCH PER 2000 BTUH 100 SQ. INCH MINIMUM (EACH) CONFINED SPACE ALL AIR FROM OUTDOORS USING HORIZONTAL DUCTS Figure 6. ALTERNATIVE OPENING LOCATION CONFINED SPACE ALL AIR FROM OUTDOORS - USING A SINGLE PERMANENT OPENING Figure 7.
  • Page 10 COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS • The connector must be firmly attached and sealed to prevent it from falling out. • To aid in removing the connector, a thimble or slip joint may be used. • The connector must not extend beyond the inner edge of the chimney as it may restrict the space between it and the opposite wall of the chimney...

  • Page 11: Know The Water Heater's Component Parts

    KNOW THE WATER HEATER’S COMPONENT PARTS Electronic Control Display (Upper Control) The Electronic Control Display panel used on this water heater provides an easy-to-read, eye level display for temperature adjustment, fault code diagnostics and recall, powered anode rod operation and setting the temperature scale for either Fahrenheit (°F) or Celsius (°C).
  • Page 12 KNOW THE WATER HEATER’S COMPONENT PARTS Burner/Manifold Door Assembly The burner/manifold door assembly consists of several components such as: main burner, burner orifice, manifold tube and flame sense / hot surface igniter. See figure below for the complete list of components (Figure 13).
  • Page 13 KNOW THE WATER HEATER’S COMPONENT PARTS Flammable Vapor Cut Off Switch (FV Sensor) The water heater is equipped with a FV sensor, for detecting the presence of flammable vapors (e.g. spilled gasoline). When the sensor detects those vapors, the heater will shut down and not operate. If flammable vapors are detected or the sensor is inoperative, an icon will flash on the electronic control display and the heater will go into a lockout...

  • Page 14: Water Heater Operation

    The figure below shows the water heater’s sequence of operation when a call for heat is initiated. The gas control valve/thermostat will attempt to light the burner three times. If the flame sense rod in the burner/ manifold assembly does not detect ignition, the control will enter lockout mode indicated by the electronic control display’s flashing of the appropriate status code.

  • Page 15: Filling And Draining The Water Heater

    FILLING, DRAINING AND FLUSHING THE WATER HEATER TANK It is recommended that the tank be drained and flushed every 6 months to remove sediment which may build up during operation. The water heater should be drained if being shut down during freezing temperatures.

  • Page 16: Lighting Instructions

    Read and understand these directions thoroughly before attempting to operate the water heater. Make sure the view port is not missing or damaged. Make sure the tank is completely filled with water before operating the water heater. The gas control valve/thermostat has an “On/Off Switch” and needs to be turned on before the water heater is operational.

  • Page 17: Adjusting The Temperature On The Electronic Control Display

    ADJUSTING THE TEMPERATURE ON THE ELECTRONIC CONTROL DISPLAY Adjusting the Temperature Set Point - The thermostat of this water heater has been factory set at its lowest position. It is adjustable and must be reset to the desired temperature setting to reduce the risk of scald injury.

  • Page 18: Using The Electronic Control Display

    USING THE ELECTRONIC CONTROL DISPLAY How to select or change the temperature scale from Fahrenheit (°F) to Celsius (°C). 1. The temperature scale defaults to Fahrenheit (°F). 2. To change to Celsius (°C), press the two temperature adjustment buttons at the same time for more than five (5) seconds but less than 10 seconds to enter the Temperature Scale Selection mode.
  • Page 19 USING THE ELECTRONIC CONTROL DISPLAY Reviewing Fault Codes: 1. Press the red up arrow button one time. 2. The display will show either E0 or E1. 3. If E0 is shown, there are no faults. By pressing the up arrow button again the display will exit the Field Service mode, or the control will exit automatically after no button is pressed for five (5) seconds.

  • Page 20: Electronic Control Display Troubleshooting

    ELECTRONIC CONTROL DISPLAY TROUBLESHOOTING Please check guidelines below. For your safety, water heater service should be performed only by a qualified service person. GENERAL SAFETY INFORMATION Read the CONTROL DISPLAY STATUS “POWER” Flashing “HEATING” and “SHORT” Flashing “HEATING” and “OPEN” Flashing “HEATING”, “OPEN”, and “SHORT”...

  • Page 21: Control Display Troubleshooting

    CONTROL DISPLAY TROUBLESHOOTING CONTROL DISPLAY STATUS “P-SW”, “OPEN”, and “CLEAN SCREEN” Flashing “P-SW” and “SHORT” Flashing “IGN” Flashing “FV-SENSE” Flashing PROBLEM 1. Clean the screen on the combustion air The air pressure switch contacts intake chamber. Turn the power “OFF” for 10 to 20 seconds then “ON”...
  • Page 22 CONTROL DISPLAY TROUBLESHOOTING CONTROL DISPLAY STATUS “FV-SENSE” Flashing (Continued from previous page) “LDO-SW”, “OPEN”, and “CLEAN SCREEN” Flashing “FV-SENSE” and “OPEN” Flashing “FV-SENSE” and “SHORT” Flashing “THMSTR” and “OPEN” Flashing “THMSTR” and “SHORT” Flashing All Segments Flashing “P-ANODE” and “OPEN” Flashing “P-ANODE”...

  • Page 23: Troubleshooting Flowchart

    TROUBLESHOOTING FLOWCHART APPLY POWER TO APPLIANCE REQUEST FOR HEAT PRESENT? WAIT FOR PRESSURE SWITCH TO OPEN PRESSURE SWITCH DISPLAY ERROR PROVEN OPEN WITHIN NUMBER SECONDS? COMBUSTION FAN ON WAIT FOR PRESSURE PRESSURE SWITCH SWITCH TO CLOSE PROVEN CLOSED DISPLAY ERROR WITHIN NUMBER SECONDS?

  • Page 24: External Inspection And Cleaning

    EXTERNAL INSPECTION AND CLEANING Cleaning the Air Intake Chamber Screen: • At least twice annually the air intake chamber screen should be inspected for any dust or debris that may have accumulated on the louvers. NOTE: If the water heater is located in an area that is subjected to lint, pet hair or dirt, it may be necessary to check the air intake chamber screen more frequently.

  • Page 25: Electronic Control Display Removal / Replacement

    ELECTRONIC CONTROL DISPLAY REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Removing the Electronic Control Display: 1.

  • Page 26: Powered Anode Removal / Replacement

    POWERED ANODE ROD REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Ratchet with 1- 1/16 ” Socket, Pliers, and Teflon ®...
  • Page 27 Installing the Powered Anode Rod: 8. Use Teflon ® tape or an approved pipe sealant on threads of the new powered anode rod. 9. Prior to installing, it will be necessary to use pliers to bend up approximately 90° the electrical male connector on the top of the powered anode rod.

  • Page 28: Pressure Switch Removal / Replacement

    PRESSURE SWITCH REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Phillips Head Screwdriver. Removing the Pressure Switch: 1.

  • Page 29: Transformer Removal / Replacement

    TRANSFORMER REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Ratchet with 5/16 Driver, Phillips Head Screwdriver. Removing the Transformer: 1.
  • Page 30 Installing the New Transformer: 10. Insert the wiring connector that goes to the gas control valve/thermostat through the wire protector on the side of the transformer box (Figure 44). 11. Attach the two (2) flag terminal connectors to the transformer by aligning and pressing down (Figure 44).

  • Page 31: Air Intake Chamber Box Removal / Replacement

    AIR INTAKE CHAMBER BOX REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Phillips Head Screwdriver. Removing the Air Intake Chamber Box: 1.
  • Page 32 14. Rotate the top of the air intake chamber box from left to right (only a few inches in both directions) while pulling outward at the bottom removing the air intake chamber box from the combustion chamber pipe saving the air intake chamber gasket for reinstallation (Figure 49).
  • Page 33 25. Install the air intake chamber box by rotating the top of the air intake chamber box from left to right (only a few inches in both directions) while pressing on the bottom portion of the air intake chamber box. When properly installed the air intake chamber box will be in place against the water heater’s side aligning with the screw holes.

  • Page 34: Wiring Harnesss Removal / Replacement

    WIRING HARNESS REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Phillips Head Screwdriver. Removing the Air Intake Chamber Box: 1.
  • Page 35 Replacing the Wiring Harness: 13. Locate the male to female electrical connection with close pin lock on wiring harness (located on the right side of fan) (Figure 62). 14. To separate the electrical connection of the fan and wiring harness: press down on the back portion of the close pin lock of the electrical connection while pulling the connection in the opposite directions.
  • Page 36 25. Install the air intake chamber screen, ensuring that the prongs of the lower portion of the air intake chamber screen are in place in the holding slots. Using the 2 screws removed in step 8, secure the air intake chamber screen (Figure 65). 26.

  • Page 37: Air Intake Chamber Fan Removal / Replacement

    AIR INTAKE CHAMBER FAN REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Phillips Head Screwdriver. Removing the Fan from the Air Intake Chamber: 1.
  • Page 38 Installing the Fan in the Air Intake Chamber Box: 11. Plug the electrical connections of the new fan into the wiring harness: Align the electrical connections in such a position as to ensure the locking portions of the connections are on the same side.

  • Page 39: Pressure Tubing Removal / Replacement

    PRESSURE TUBING REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: Phillips Head Screwdriver. Removing the Air Intake Chamber Box: 1.
  • Page 40 Installing the Air Intake Chamber Box: 11. Check the position the wiring harness wire in the wiring channeling molded down the back center of the air intake chamber box (Figure 78). 12. Connect the air pressure tubing to the fitting on the bottom of the air intake chamber box and route tubing in molded inlaid of the air intake chamber box (Figure 78).

  • Page 41: Inner Door/Manifold/Burner Assembly Removal / Replacement

    INNER DOOR/MANIFOLD/BURNER ASSEMBLY REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: 3/4” Open-End Wrench or Crescent Wrench, Phillips Head Screwdriver, Ratchet with 1/4”...
  • Page 42 Installation Caution Must Be Taken: 10. Prior to installing the new inner door/manifold/ burner assembly, look inside the burner chamber to fully understand the correct positioning of the burner assembly and burner manifold tab. It may be necessary to use a flashlight to ensure correct placement.

  • Page 43: Flame Sense/Hot Surface Igniter Removal / Replacement

    FLAME SENSE/HOT SURFACE IGNITER REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: 3/4” Open-End Wrench or Crescent Wrench, Phillips Head Screwdriver, Ratchet with 1/4”...

  • Page 44: Burner Removal / Replacement

    Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: 3/4” Open-End Wrench or Crescent Wrench, Phillips Head Screwdriver, Ratchet with 1/4” socket or 1/4”...
  • Page 45 Removing Old Burner : 11. After noting the position of the condensation drain hole on the top of the burner. Turn the inner door/ manifold/burner assembly upside. Using a phillips head screwdriver remove the 2 screws attaching the burner to the manifold pipe (saving screws for reinstallation later) (Figure 99).
  • Page 46 16. After confirming no material of any type are between door gasket and combustion chamber shield, align the screws on the inner door with the screw holes on the combustion chamber and tighten with 1/4” nut driver or 1/4” socket & ratchet (Figure 97).

  • Page 47: Burner Orifi Ce Removal / Replacement

    BURNER ORIFICE REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: 3/4” Open-End Wrench or Crescent Wrench, Phillips Head Screwdriver, Ratchet with 1/4”...
  • Page 48 Removing Old Burner Orifice : 11. Burner may be hot, wait until burner has cooled off. After noting the position of the condensation drain hole on the top of the burner. Turn the inner door/manifold/burner assembly upside. Using a phillips head screwdriver remove the 2 screws attaching the burner to the manifold pipe (saving screws for reinstallation later) (Figure 108).
  • Page 49 Reinstalling The Inner Door/Manifold/Burner Assembly 17. Insert the manifold/burner assembly in the burner chamber compartment, making sure that the tip of burner manifold tab engages in the slot of the bracket (Figure 107). The tip end of the burner manifold MUST be placed in the slotted portion under the condensation pan to obtain proper installation (Figure 107).

  • Page 50: Gas Control Valve/Thermostat Removal / Replacement

    GAS CONTROL VALVE/THERMOSTAT REMOVAL / REPLACEMENT Important: Use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a qualified service technician. Tools required: 3/4” Open-End Wrench or Crescent Wrench, Phillips Head Screwdriver, a short length of 1/2”...
  • Page 51 11. Ensuring that the gas supply line is turned off, disconnect the gas piping at the ground joint union, then remove the gas piping from the gas control valve/ thermostat (Figure 116). 12. Remove any other fittings that may be installed on the threaded pipe to the gas control valve/thermostat (Figure 116).

  • Page 52: Checking The Gas Supply Pressure

    23. Turn on the gas supply to the unit and test the gas supply line and union connections by brushing on an approved noncorrosive leak detection solution (Figure 116). 24. Turn on the electrical and the gas supplies to the water heater.

  • Page 53: Gas Water Heater Sizing Guide -And- Leakage Checkpoints

    GAS WATER HEATER SIZING GUIDE Use the following information as a guide to approximate the correct size water heater for the residence: • 40 gallon size (28 gallon draw) for two bath residence -or one bath with an automatic clothes washer. •...

  • Page 54: General 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 (60% is the minimum).
  • Page 55 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.) 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.
  • Page 56 ALL TECHNICAL AND WARRANTY QUESTIONS SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED. IF YOU ARE UNSUCCESSFUL, CONTACT A O SMITH WATER HEATERS RESIDENTIAL TECHNICAL ASSISTANCE AT 1-800-527-1953 OR WWW.HOTWATER.COM.

This manual is also suitable for:

12 50gpc t 100Gahh 40 100Gahh 50 100Gp 6 40ypc t 100Gp 6 50ypc t 100Pcg250t403nov 100 ... Show all

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