A.O. Smith AOSRG45200

Questions and Answers

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Angela KerrAug 12, 2025
Why is my A.O. Smith AOSRG45200 Water Heater not producing enough hot water?
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  evanstroyAug 12, 2025
  If your A.O. Smith Water Heater isn't providing enough hot water, several factors could be the cause. Ensure the heater is lit and the thermostat is on by checking the lighting instructions. The thermostat might be set too low, so check the temperature regulation. If the heater is undersized, try reducing hot water use. Other potential issues include low gas pressure (contact your dealer), unusually cold incoming water (allow more reheat time), leaking hot water pipes (have a plumber repair them), or a high-temperature limit switch activation (contact your dealer).
J
Joanna JonesAug 16, 2025
How to fix water leaks in A.O. Smith AOSRG45200?
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  Bradley MccoyAug 16, 2025
  If you notice water leaks in your A.O. Smith Water Heater, start by tightening the threaded connections on the hot or cold supply, relief valve, drain valve, or thermostat. Also, inspect nearby appliances and water lines for any leakage. Condensation of flue products might also be the reason, refer to CONDENSATION.
D
Donald GarciaAug 19, 2025
What to do if pilot keeps going out on A.O. Smith Water Heater?
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  John GonzalezAug 19, 2025
  If your A.O. Smith Water Heater's pilot light keeps going out, the pilot burner might be dirty; try cleaning the pilot assembly. Ensure the thermocouple tip is correctly positioned in the pilot flame. If problems continue, the thermocouple may be malfunctioning and require replacement. Check the thermostat.
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Lisa NewtonAug 23, 2025
How to fix A.O. Smith AOSRG45200 pilot that will not light?
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  Susan StoneAug 23, 2025
  If the pilot on your A.O. Smith Water Heater won't light, refer to the LIGHTING INSTRUCTIONS. The pilot orifice might be clogged, requiring cleaning or replacement. A pinched or clogged pilot tube may also be the reason, replace the pilot tube. Ensure the main gas supply is turned on.
K
katrina76Aug 27, 2025
What causes A.O. Smith Water Heater water to be too hot?
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  williamsdawnAug 27, 2025
  If the water from your A.O. Smith Water Heater is too hot, the thermostat might be set too high. Refer to HIGH TEMPERATURE REGULATION to adjust it.
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Sarah AndersonAug 30, 2025
Why is the T & P valve leaking on my A.O. Smith AOSRG45200?
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  qlopezAug 30, 2025
  If the T & P valve on your A.O. Smith Water Heater is leaking, it could be due to thermal expansion in a closed water system; install a thermal expansion tank (DO NOT plug the T & P valve). It may also be due to improperly seated valve. Check the relief valve for proper operation (DO NOT plug the T & P valve).
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Christopher RiddleSep 3, 2025
How to get rid of hot water odors in A.O. Smith AOSRG45200?
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  Joshua PriceSep 3, 2025
  If your A.O. Smith Water Heater has hot water odors, it could be due to high sulfate or mineral content in the water supply. Drain and flush the heater thoroughly, then refill it. Another possibility is bacteria in the water supply, in that case chlorinate the water supply.
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Brianna McmahonSep 7, 2025
Why does my A.O. Smith AOSRG45200 Water Heater make sizzling or rumbling sounds?
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  Preston Baker MDSep 7, 2025
  If your A.O. Smith Water Heater is making sizzling or rumbling sounds, it might be due to condensation dripping on the burner; refer to CONDENSATION. Sediment at the bottom of the tank could also be the cause; clean the sediment from the tank by referring to the DRAINING instructions in the Maintenance section of the manual.

Summary

Get to Know Your Water Heater

Replacement Parts and Deliming Products

Information on ordering replacement parts and recommended delimer products for the water heater.

Water Heater Components Diagram

Detailed diagrams and identification of water heater components and their functions.

General Safety Information

External Damage Warnings

Instructions for checking the water heater after damage, fire, flooding, or exposure to fire.

Chemical Vapor Corrosion Risks

Warning about corrosive chemicals affecting the vent system and potential failure.

Improper Combustion Hazards

Risks of attic fans, negative draft, and ensuring adequate combustion air.

Liquid Petroleum Model Precautions

Precautions for water heaters using propane (LPG) versus natural gas.

Extended Non-Use Period Safety

Safety warning regarding hydrogen gas production during long periods of non-use.

Insulation Blanket Installation Guidelines

Guidelines and warnings for installing insulation blankets on the water heater.

Installation

Required Installation Ability

Specifies the required skills and qualifications for installing the water heater.

General Installation Requirements

Covers general requirements, local codes, and standards compliance for installation.

Heater Location and Clearances

Guidance on selecting an appropriate location, considering necessary clearances.

Air Requirements for Combustion

Details on air for combustion and ventilation in confined/unconfined spaces.

Flammable Vapors Safety Warning

Critical safety warning about explosion risk from flammable vapors near the heater.

Water and Gas Connections

Instructions for connecting water and gas supply lines safely.

Draft Hood and Venting Installation

Proper installation of the draft hood and connection to the venting system.

Relief Valve and Pipe Insulation

Installation of the temperature and pressure relief valve and pipe insulation.

Operation

Filling the Water Heater

Step-by-step instructions for filling the water heater with water before operation.

High Altitude Installation Adjustments

Important considerations and potential modifications for installations above 4000 ft.

Safety Before Lighting Appliance

Critical safety warnings and procedures to follow before lighting the appliance.

Lighting Instructions

Detailed step-by-step guide for safely lighting the pilot light and main burner.

Shutting Off Gas Supply

Procedure for safely turning off the gas supply to the water heater.

Maintenance and Troubleshooting

Draft Hood Operation Check

How to check the proper functioning of the draft hood under building depressurization.

Temperature Regulation and Scald Risk

Information on adjusting water temperature and warnings about scald hazards.

Pilot and Main Burner Check

Guidelines for checking pilot and main burner flame characteristics annually.

High Temperature Limit Switch

Explanation of the built-in limit switch and its function in case of excessive temperatures.

Venting System Inspection

Recommendation to check the venting system every twelve months for obstructions.

Temperature and Pressure (T&P) Valve Check

Instructions for checking the temperature and pressure relief valve's operation annually.

Draining the Water Heater

Procedure for draining the heater to prevent damage from freezing.

Condensation Issues

Explanation of condensation on tank surfaces and potential causes.

Cathodic Protection and Anode Rod

Information about the anode rod's role in corrosion protection and potential odor issues.

Anode Rod Maintenance

Guidance on inspecting and replacing the anode rod for tank longevity.

Troubleshooting Water Leaks

Common causes and solutions for water leaks from connections or components.

Troubleshooting Leaking T&P Valve

Troubleshooting steps for a leaking temperature and pressure relief valve.

Troubleshooting Hot Water Odors

Addressing odors in hot water, often related to water content or bacteria.

Troubleshooting Pilot Outage

Common causes and solutions for the pilot light going out.

Troubleshooting Pilot Not Lighting

Troubleshooting steps when the pilot light fails to ignite.

Troubleshooting No Hot Water

Identifying and resolving issues causing insufficient or no hot water supply.

Troubleshooting Water Too Hot

Diagnosing and fixing problems causing the water to be excessively hot.

Troubleshooting Sizzling;Rumbling Sounds

Explaining common sounds like sizzling or rumbling and their causes.

Troubleshooting Sooting

Troubleshooting steps for sooting, indicating improper combustion.

Limited Residential Gas Warranty

Warranty Periods Explained

Details on the warranty duration for different models and parts.

Warranty Conditions and Exceptions

Terms and conditions that apply to the warranty coverage.

Service and Labor Responsibility

Clarifies costs covered by warranty versus owner responsibilities.

Limitation on Implied Warranties

Limitations on implied warranties such as merchantability.

Warranty Claim Procedure

Steps to follow when initiating a warranty claim.

Warranty Disclaimers

Legal disclaimers regarding express/implied warranties and liability.

Important Warranty Information

Section for recording essential details like model number, serial number, and installation date.

A.O. Smith AOSRG45200 Specifications

General

Brand	A.O. Smith
Model	AOSRG45200
Fuel Type	Natural Gas
Capacity	50 gallons
First Hour Rating	90 gallons
Energy Factor	0.62
Warranty	6 years
Vent Type	Atmospheric
Type	Gas