A.O. Smith 300 Series Instruction Manual

A.O. Smith 300 Series Instruction Manual

Residential gas water heaters. power vent/power direct vent gas models with direct spark ignition
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LOW LEAD
CONTENT
WARNING: If the information in these
instructions is not followed exactly, a fire
or explosion may result causing property
damage, personal injury or death.
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do
not use any phone in your building.
Immediately call your gas supplier
from a neighbor's phone. Follow the
gas supplier's instructions.
If you cannot reach your gas supplier,
call the fire department.
Installation
and
performed by a
service agency or the gas supplier.
Thank you for buying this energy efficient water
heater. We appreciate your confidence in our
products.
ALL TECHNICAL AND WARRANTY QUESTIONS: SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED.
IF YOU ARE UNSUCCESSFUL, CALL THE TECHNICAL SUPPORT PHONE NUMBER SHOWN ON THE WATER HEATER LABELING.
KEEP THIS MANUAL IN THE POCKET ON HEATER FOR FUTURE REFERENCE WHENEVER MAINTENANCE
PRINTED 1020
service
must
be
qualified
installer,
ADJUSTMENT OR SERVICE IS REQUIRED.
Instruction Manual
RESIDENTIAL GAS WATER HEATERS
POWER VENT/POWER DIRECT VENT GAS MODELS
Read and understand this instruction
manual and the safety messages
herein before installing, operating or
servicing this water heater.
Failure to follow these instructions and
safety messages could result in death
or serious injury.
This manual must remain with the
water heater.
• For Your Safety •
AN ODORANT IS ADDED TO THE GAS USED BY
THIS WATER HEATER.
WITH DIRECT SPARK IGNITION
300/301 SERIES MODELS
CANADIAN MANUAL
100338022_2000557009D

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Summary of Contents for A.O. Smith 300 Series

  • Page 1 Instruction Manual RESIDENTIAL GAS WATER HEATERS POWER VENT/POWER DIRECT VENT GAS MODELS WITH DIRECT SPARK IGNITION 300/301 SERIES MODELS CANADIAN MANUAL LOW LEAD CONTENT WARNING: If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury or death.
  • Page 2: Table Of Contents

    CONTENTS CONTENTS Concentric Vent Installation ..........31 SAFE INSTALLATION, USE AND SERVICE ...... 3 Low Profile Termination Installation ........33 APPROVALS ................. 3 WATER HEATER INSTALLATION ........35 GENERAL SAFETY INFORMATION ........4 Condensate Drain Installation .......... 35 Precautions ................ 4 Limiting the Risk of Scalding ..........
  • Page 3: Safe Installation, Use And Service

    SAFE INSTALLATION, USE AND SERVICE SAFE INSTALLATION, USE AND SERVICE The proper installation, use and servicing of this water heater is extremely important to your safety and the safety of others. Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn you and others of a potential injury hazard.
  • Page 4: General Safety Information

    GENERAL SAFETY INFORMATION GENERAL SAFETY INFORMATION Higher tank temperatures (140°F) also kill bacteria that cause a PRECAUTIONS condition known as “smelly water” and can reduce the levels of DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN bacteria that cause water-borne diseases. EXPOSED TO FLOODING OR WATER DAMAGE.
  • Page 5 Breathing Hazard - Carbon Monoxide Gas Explosion Hazard • Install vent system in accordance with codes. Overheated water can cause • Do not operate water heater if any part has been exposed to flooding or water damage. water tank explosion. •...
  • Page 6 Fire or Explosion Hazard Fire Hazard Do not store or use gasoline or other flammable vapors and For continued protection against liquids in the vicinity of this or any other appliance. risk of fire: Avoid all ignition sources if you smell gas. Do not install water heater on carpeted floor.
  • Page 7: Introduction

    INTRODUCTION INTRODUCTION Thank You for purchasing this water heater. Properly installed and Particular attention should be given to the installation of maintained, it should give you years of trouble free service. thermometers at the locations indicated in the piping diagrams as these are necessary for checking the operation of the water ABBREVIATIONS USED heater.
  • Page 8: Dimensions And Capacity Data

    DIMENSIONS AND CAPACITY DATA DIMENSIONS AND CAPACITY DATA ROUGH IN DIMENSIONS Figure 1. Dimensions for 50 Gallon Unit FRONT VIEW BACK VIEW Figure 2. (1A) Dimensions for 75 Gallon Unit Table 1. Rough-In-Dimensions Units Inches 66.75 49.25 22.00 15.75 3.00 8.00 8.00 62.00...
  • Page 9 Table 2. TCapacity, Gas and Electrical Characteristics Approximate Capacity *Manifold Pressure Electrical Characteristics Amperes U.S. Gals. Liters Gas Type “WC Volts/Hz Nat./LP 120/60 <5 Nat/LP 120/60 <5 * The manifold pressure is the factory setting and is not adjustable. A negative pressure will be seen with just the blower running without the Gas Control Valve open.
  • Page 10: Features And Components

    FEATURES AND COMPONENTS FEATURES AND COMPONENTS CAUTION HARNESS HAS 120 VAC. IN OPERATION. ** See Venting Installation (page 23) and Condensate Piping (page 21) for more information. **13 **14 Access Panel Caution: This access panel covers a 2” NPT plug that was required during the man- ufacturing of this water heater.
  • Page 11 CAUTION HARNESS HAS 120 VAC. IN OPERATION. ** Venting Installation (page 23) and Condensate Piping (page 21) for more information. **13 **14 Access Panel Caution: This access panel covers a 2” NPT plug that was required during the man- ufacturing of this water heater.
  • Page 12: Controls And Switches

    CONTROLS AND SWITCHES This model is provided with two pressure switches. These switches unit down whenever there is a failure of either of the switches. It is are essential to the safe and proper operation of the unit. The important to understand the purpose of both switches. switches are wired in series.
  • Page 13: Installation Considerations

    INSTALLATION CONSIDERATIONS INSTALLATION CONSIDERATIONS LOCATING THE WATER HEATER Carefully choose a location for the new water heater. The placement is a very important consideration for the safety of the occupants in Fire or Explosion Hazard the building and for the most economical use of the water heater. Do not store or use gasoline or other flammable vapors and CAUTION liquids in the vicinity of this or any other appliance.
  • Page 14: Insulation Blankets

    Minimum clearances between the water heater and combustible Do obtain new warning and instruction labels from the • construction are 0 inch at the sides and rear, 5.5” (14.0 cm) from manufacturer for placement on the blanket directly over the the front and 18”...
  • Page 15 these illustrations for the purpose of vent installation. See Venting UNCONFINED SPACE Installation on Page 24 for complete venting installation instructions. An Unconfined Space is one whose volume IS NOT LESS THAN 50 cubic feet per 1,000 Btu/hr (4.8 cubic meters per kW) of the Outdoor Air Through Two Openings total input rating of all appliances installed in the space.
  • Page 16 Air From Other Indoor Spaces 1 square inch per 3000 Btu/hr (733 mm per kW) of the total input rating of all appliances located in the enclosure, and Not less than the sum of the areas of all vent connectors in the space.
  • Page 17: Installation Requirements

    INSTALLATION REQUIREMENTS INSTALLATION REQUIREMENTS CHEMICAL VAPOR CORROSION Water temperature over 125°F (52°C) can cause severe burns instantly Corrosion of the flueways and vent system may occur if air for resulting in severe injury or death. combustion contains certain chemical vapors. Such corrosion may result in failure and risk of asphyxiation.
  • Page 18: Thermostatic Point-Of-Use Mixing Valves

    A high quality power supply filter/suppressor must be installed if the In all cases, the following burn table must be used. above conditions exist. Call the technical support phone number Table 3. Time to Burn at Different Temperatures Time for Permanent listed on the back cover of this manual for more information.
  • Page 19: Supply Gas Regulator

    This water heater is not to be used as a replacement for an SUPPLY GAS REGULATOR • existing boiler installation. The maximum allowable gas supply pressure for this water heater Do not use with piping that has been treated with chromates, is 14 inches W.C.
  • Page 20: Closed Water Systems

    couplings be installed on this water heater when connected to copper pipe. See Figure 14 (page 20) also. Burn Hazard To reduce the risk of unusually hot water reaching the fixtures in the house, install thermostatic mixing valves at each point of use. Note: Solar water heating systems can often supply water with temperatures exceeding 180°F (82.2°C) and may result in water heater malfunction.
  • Page 21: T&P Valve Discharge Pipe Requirements

    must also have its own properly sized, rated and approved Shall be installed so as to allow complete drainage of both the • Temperature-Pressure Relief Valve installed. Temperature-Pressure Relief Valve and the discharge pipe. Must terminate a maximum of twelve inches (300 mm) above a •...
  • Page 22: Condensate Ph Level

    Note: If the “Blocked Exhaust “ Fault message is ever displayed FILLING THE WATER HEATER on the control system LCD, check the condensate drain first and ensure it is not blocked. THIS SIDE VIEW EXHAUST (VENT) OF EXHAUST ELBOW ELBOW AND ARROW INDICATE CONDENSATE THE LOCATION OF...
  • Page 23: Venting Installation

    VENTING INSTALLATION VENTING INSTALLATION Approved vent pipe materials that must be used: • ULC S636 PVC / CPVC Breathing Hazard - Carbon Monoxide Gas ULC S636 Polypropylene - See Polypropylene Installations (page • 24). • Install vent system in accordance with codes. •...
  • Page 24: Back-Flow Preventer

    BACK-FLOW PREVENTER Insulation should not be used on Polypropylene venting materials. The use of insulation will cause increased vent wall temperatures, The air inlet of this heater includes a back-flow preventer (Illustration which could result in vent pipe failure. shown above) that keeps moist, hot air from rising out of the heater Use only the adapters and vent system listed in Tables below.
  • Page 25: Planning The Vent System

    Drill a pilot hole approximately one quarter inch (0.64 cm) PLANNING THE VENT SYSTEM outside of the marked circle. This pilot hole is used as a starting Do not locate the vent termination over public walkways or a public point for a saws-all or sabre saw blade. Cut around the marked area where condensate or vapor can cause a nuisance or ice hazard.
  • Page 26: Direct Vent Air Intake Moisture Protection

    Note: To prevent exhausting products from circulating to the air Glue the air intake terminal to the section of the pipe. intake in windy/cold areas, the maximum practical distance Slide the wall plate over pipe to stop against air intake terminal. between these two terminals is recommended.
  • Page 27 Figure 21. Vertical Vent Termination Separation Clearance Figure 22. Pitched Roof Vertical Vent Termination Snow Clearances Figure 23. Flat Roof Vertical Intake Clearance from Nearby Structures...
  • Page 28: Sidewall Termination Direct Vent Clearances

    SIDEWALL TERMINATION DIRECT VENT CLEARANCES Inside corner detail 15 ft Fixed closed Operable Fixed Closed Operable Regulator vent outlet In the event no regulator is present, Legend: H and I can be = Area where terminal is not permitted = Vent terminal = Air supply inlet disregarded Figure 24.
  • Page 29: Sidewall Termination Clearances Other Than Direct Vent

    SIDEWALL TERMINATION CLEARANCES OTHER THAN DIRECT VENT Inside corner detail 15 ft Fixed closed Operable Fixed Closed Operable Regulator vent outlet In the event no regulator is present, Legend: H and I can be = Area where terminal is not permitted = Vent terminal = Air supply inlet disregarded...
  • Page 30: Direct Vent Diagram

    DIRECT VENT DIAGRAM DIRECT VENT INSTALLATIONS 24” minimum separation. Direct Vent combustion air intake drains are required in certain Exhaust must situations. See Direct Vent Air Intake Moisture Protection (page 26) and be at same level 24” or above intake the Figure 26 and Figure 28 (page 30) below.
  • Page 31: Concentric Vent Installation

    Cut one hole (5 in. diameter). CONCENTRIC VENT INSTALLATION Partially assemble concentric vent termination kit. This water heater is certified for concentric venting with concentric vent kit #100111100. Follow the instructions below for proper A. Cement Y concentric fitting to larger diameter kit pipe. See installations.
  • Page 32 Cement water heater combustion air intake and vent pipes to Determine best location for termination kit. concentric vent termination assembly. See Figure 33 (page 31) Note: Consideration for the following should be used when for proper pipe attachment. determining an appropriate location for the termination kit: Operate heater through 1 heat cycle to ensure combustion air and •...
  • Page 33: Low Profile Termination Installation

    Cement heater combustion-air and vent pipes to concentric vent LOW PROFILE TERMINATION INSTALLATION termination assembly. See Figure 36 (page 33) for proper pipe This water heater is certified for sidewall direct venting with IPEX orientation and attachment. System 636 Low Profile Vent Kit. Follow instructions below for Operate heater through one heat cycle to ensure combustion- proper installations.
  • Page 34 To Heater Intake Air Connection From Heater Vent Pipe Connection 12” Min to Possible Orientations Over- Hang Vent/Air Termination 12” Grade or Snow Line Figure 40. Low-Profile Vent Clearances 12” Min between Edge of Air Inlet Vent (Exhaust) and Adjacent Vent (Exhaust) Outlet Air Inlet Vent/Air Termination...
  • Page 35: Water Heater Installation

    WATER HEATER INSTALLATION WATER HEATER INSTALLATION CONDENSATE DRAIN INSTALLATION INSTALLATION INSTRUCTIONS Ensure the water heater’s Enable/Disable switch is in the Installation must conform with these instructions and local building “Disable” position. codes. Install a 1/2 inch PVC condensate drain line between condensate Field supplied materials required for installation include: drain connection on the Exhaust/Condensate Elbow and a Approved PVC cement and PVC primer.
  • Page 36 Contaminants in the gas lines may cause improper operation of the Note: This water heater should not be connected to an electrical gas control valve that may result in fire or explosion. Before attaching supply with a Ground Fault Circuit Interrupter (GFCI) or Arc the gas line be sure that all gas pipe is clean on the inside.
  • Page 37 Note: Whenever the external control opens the set of dry contacts used, water heating operation is disabled. Whenever the external control closes the set of dry contacts used, water heating operation is enabled. A diagonal line and circle appears over the thermometer icon on the UIM when water heating operation is disabled.
  • Page 38: Temperature Regulation

    TEMPERATURE REGULATION TEMPERATURE REGULATION In addition to using the lowest possible temperature setting that HIGH TEMPERATURE LIMIT CONTROL (ECO) satisfies the demand of the application a mixing valve can be installed This water heater is equipped with an ECO (energy cut out) non at the water heater or at the hot water taps to further reduce system adjustable high temperature limit switch.
  • Page 39: High Temperature Applications

    HIGH TEMPERATURE APPLICATIONS Higher operating temperatures cause more wear on all water heaters and will decrease the life span of the water heater. Consider installing a small booster water heater for high temperature applications to raise the outlet temperature from the larger primary water heater to the desired point of use temperature.
  • Page 40: Control System Operation

    CONTROL SYSTEM OPERATION CONTROL SYSTEM OPERATION POWER LIMITING THE RISK OF SCALDING SUPPLY For a variety of reasons, water heaters can produce water that is BOARD much hotter than its temperature setting. Take precautions to prevent this higher temperature water from reaching the water fixtures. BOARD Burn Hazard To reduce the risk of unusually hot...
  • Page 41 LCD Touch Display Title Bar Information Operating Set Point 120°F Display Status: Heating Status Icons MENU HELP Enable/Disable Switch* * See the Features and Components section of this Operational menus are multi functional. manual for the precise location. Figure 45. User Interface Module (UIM) Desktop Screen STATUS ICONS The Status Icons are displayed on the Desktop screen and convey operational and diagnostic information.
  • Page 42 OPERATING STATES The current operational state of the water heater is displayed on the Desktop screen as the “Status.” The common operational states are described in the table below. Table 12. Operating States State Description Standby The water heater is not in an active heating cycle. IE: the Tank Temperature is at or above the Operating Set Point. Input Verification The control system is conducting a diagnostic check at the beginning of a heating cycle.
  • Page 43: User Settings & Control System Menus

    USER SETTINGS & CONTROL SYSTEM MENUS TEMPERATURES MENU Burn Hazard OPERATING SET POINT AND DIFFERENTIAL ADJUSTMENT The Operating Set Point is adjustable from 90°F (42°C) to 160°F To reduce the risk of unusually hot (71°C). The factory setting is 120°F (49°C). The Differential is water reaching the fixtures in the adjustable from 2°...
  • Page 44 Temperatures Menu Description/Action Display Use the "+" and "-" Buttons to change the current setting. Operating Setpoint ° Press "ACCEPT" to save the new setting. Press "BACK" to discard changes and return to the previously saved setting. ° ° Note: Use this procedure to change the Differential setting and other adjustable user settings in the control system menus.
  • Page 45 Heater Status Menu Description/Action Display Top of Menu Press Heater Status from the Main Menu to enter this menu. This Heater Status menu contains non adjustable operational information. Use the Status: Standby slidebar to navigate the menu. Status - displays the current Operating State. See Table 12 ECO Contact Closed •...
  • Page 46 Heater Information Description/Action Display Press Heater Information from the Main Menu to enter this menu. Top of Menu This menu contains non adjustable operational information. Heater Information Elapsed Time - Total accumulated time the control system • Elapsed Time 0days 0hrs 43mins > (water heater) has been energized.
  • Page 47 Fault History Description/Action Display Press "Fault History" from the Main Menu to enter this menu. This Fault History menu contains non adjustable operational information. Use the Blocked Exhaust (A8) > Slidebar to navigate the menu. This menu contains a list of the last nine (9) Fault and Alert 0 days 2 hrs 37 mins ago >...
  • Page 48 their customers. This contact information will be displayed with all SERVICE CONTACT INFORMATION Fault and Alert messages. The control system has a discrete menu that Installing contractors and/or service agents can access to enter contact information for Contact Information Description/Action Display From the Desktop Screen press and hold down the middle Top of Screen...
  • Page 49 Contact Information (Continued from page 44) Description/Action Display Access Code - Displays access code utilized to enable/disable Bottom of Screen screen lock. Contact Information Enable Screen Lock - Factory default set to No. When enabled, (000) 000-0000 prevents access to any screen but the home screen and the Contact Information screen.
  • Page 50: For Your Information

    FOR YOUR INFORMATION FOR YOUR INFORMATION The smell is a result of four factors which must all be present for SMOKE/ODOR the odor to develop: It is not uncommon to experience a small amount of smoke and A. A concentration of sulfate in the supply water. odor during the initial start-up.
  • Page 51: Start Up

    START UP START UP PRIOR TO START UP FILLING THE WATER HEATER Installation and start up of this water heater requires abilities and skills equivalent to that of a licensed tradesman in the field involved. See Qualifications (page 7). DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN EXPOSED TO FLOODING OR WATER DAMAGE.
  • Page 52 FOR YOUR SAFETY READ BEFORE LIGHTING WARNING: If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life. l l i i f i l l i 6. This appliance is equipped with an ignition device which automatically lights the burner.
  • Page 53: Periodic Maintenance

    PERIODIC MAINTENANCE PERIODIC MAINTENANCE If after inspection of the vent system you found sooting or Table 14. Maintenance Schedule deterioration, something is wrong. Call the local gas utility to correct Component Interval Operation Reference Drain and Flush See Draining and Flushing (page 55). the problem and clean or replace the flue and venting before Tank Every 6 Months...
  • Page 54: Temperature-Pressure Relief Valve Test

    TEMPERATURE-PRESSURE RELIEF VALVE TEST by protecting the glass-lined tank from corrosion. Adverse water quality, hotter water temperatures, high hot water usage, hydronic heating devices, and water softening methods can increase the rate of anode rod depletion. Once the anode rod is depleted, the tank Burn hazard.
  • Page 55: Draining And Flushing

    Open a nearby hot water faucet and let the water run until the water is no longer hot. Then close the hot water faucet. Connect a hose to the drain valve and terminate it to an adequate Explosion Hazard drain. Ensure the drain hose is secured before and during the entire Temperature-Pressure Relief Valve flushing procedure.
  • Page 56: Burner Flame Inspection

    Note: Contact Technical Support for assistance in ordering the The main burner should display the following characteristics: Provide complete combustion of gas. UN-LIME ® Professional Delimer. • Cause rapid ignition and carry over of flame across entire • BURNER FLAME INSPECTION burner.
  • Page 57: Leakage Checkpoints

    LEAKAGE CHECKPOINTS LEAKAGE CHECKPOINTS Never use this water heater unless it is completely filled with water. B: Anode Rod Connection To prevent damage to the tank, the tank must be filled with water. Water must flow from the hot water faucet before turning “ON” gas A: Inlet &...
  • Page 58: Troubleshooting

    TROUBLESHOOTING TROUBLESHOOTING INSTALLATION CHECKLIST SEQUENCE OF OPERATION Read Sequence Of Operation (page 57) before attempting to correct The list below represents some of the most critical installation any operational problems. See Features and Components (page 10) requirements that, when overlooked, often result in operational problems, down time and needless parts replacement.
  • Page 59 If tank temperature drops below Operating Set Point minus Differential setting a heating cycle is activated Control System performs diagnostic checks Control System Locks Out Normal State of all pressure switches and ECO are checked Displays Fault Msg Pressure switches and ECO are verified closed Combustion Blower is energized Pre-Purge cycle Spark Ignition Transformer is energized...
  • Page 60: Operational Problems

    OPERATIONAL PROBLEMS MOMENTARY IGNITION CAUTION Burn Hazard Read and understand this instruction manual and the safety messages The combustion chamber and burner sleeve • herein before installing, operating or and housing become very hot during operation. servicing this water heater. Do not reach into the burner housing or •...
  • Page 61: Replacement Parts

    The following section, Fault And Alert Messages lists some of the REPLACEMENT PARTS messages the control system will display on the LCD when there Replacement parts may be ordered from the manufacturer, are operational problems. This is not a complete list. Along with authorized service agencies or distributors.
  • Page 62: Fault And Alert Messages

    FAULT AND ALERT MESSAGES For technical support or to locate a qualified service technician in your area, call the phone number on the warranty sheet supplied with this water heater. Fault Messages. Possible Causes - Check/Repair Displayed Fault/Alert Message Using a manometer, ensure that gas supply pressure is Ignition Failure •...
  • Page 63 Fault Messages. Possible Causes - Check/Repair Displayed Fault/Alert Message No Water Confirm the water heater is full of water. • Confirm the powered anode wire connections are tight 0 days 0 hr 0 min ago • and free of debris or moisture (i.e. rust, solder, metal pipe Error Code: D6 -8 shavings).
  • Page 64: Diagrams

    DIAGRAMS DIAGRAMS CAUTION Electrical Shock Hazard Label all wires prior to disconnection when servicing controls. ● Disconnect from electrical supply before Wiring errors can cause improper and dangerous operation. Verify servicing unit. Replace all doors and proper operation after servicing. panels before operating heater.
  • Page 65: Central Control Board (Ccb) Layout

    CENTRAL CONTROL BOARD (CCB) LAYOUT Figure 54. Central Control Board Layout...
  • Page 66 NOTES NOTES...
  • Page 67 NOTES NOTES...
  • Page 68 Copyright © 2020. All rights reserved.

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301 series

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