A.O. Smith ATI-140H-N

Other manuals for A.O. Smith ATI-140H-N

Service Handbook76 pages

Questions and Answers

D
Douglas JacksonAug 15, 2025
Why is there no hot water when I open a fixture with my A.O. Smith ATI-140H-N Water Heater?
- J
  Jocelyn AndersonAug 15, 2025
  If hot water isn't available when you open a fixture with your A.O. Smith Water Heater, ensure the unit has a 120 VAC, 60 Hz power supply. If you're using a remote or temperature controller, check if it's powered on. Also, verify that both the gas and water supply valves are fully open. Check if the filter on the cold water inlet is clean and ensure the hot water fixture is open enough to draw at least 0.5 GPM through the heater. Finally, check that the unit isn't frozen and, for propane models, that there is enough gas in the tank or cylinder.
C
Christina SmithAug 18, 2025
Why is my A.O. Smith ATI-140H-N water not hot enough?
- D
  deborahsmithAug 18, 2025
  If the water from your A.O. Smith Water Heater isn't hot enough, start by checking for cross plumbing between cold and hot water lines. Ensure the gas supply valve is fully open and that the gas line is properly sized. Also, confirm that the gas supply pressure is sufficient and that the set temperature isn't too low.
T
Tristan DavisAug 21, 2025
Why is the hot water temperature fluctuating in my A.O. Smith ATI-140H-N?
- T
  Tyler MorrisonAug 21, 2025
  If you're experiencing temperature fluctuations with your A.O. Smith Water Heater, start by checking if the filter on the cold water inlet is clean. Verify that the gas line is properly sized and the supply gas pressure is sufficient. Also, check for cross connections between the cold and hot water lines.
J
James ReyesAug 25, 2025
What to do if A.O. Smith Water Heater water is too hot?
- M
  Marissa RamosAug 26, 2025
  If the water from your A.O. Smith Water Heater is too hot, check if the set temperature is set too high.
W
William HudsonAug 28, 2025
What to do if A.O. Smith Water Heater unit does not ignite?
- D
  Dennis RichardsonAug 28, 2025
  If your A.O. Smith Water Heater isn't igniting when water flows through it, first check if the remote power button is turned on, if you are using a remote controller. Then, check if the computer board is receiving power by looking for the green LED on the board or the amber LED on the temperature/remote controller. If it's not lit, ensure the ON/OFF switch below the fuse box is in the 'on' position and that the fuse in the fuse box isn't blown.
E
Emily BarajasAug 31, 2025
How to fix A.O. Smith Water Heater not hot enough?
- A
  Alex SawyerAug 31, 2025
  If your A.O. Smith Water Heater is not providing enough hot water, start by checking the set temperature using the temperature or remote controller to ensure it's at your desired level. Also, check for construction dust and debris in venting, such as dry wall dust. If there is dust inside the cabinet, there will also be dust inside the burner and heat exchanger. Refer to “Cleaning the Combustion.”
J
josephbrooksSep 4, 2025
Why is A.O. Smith Water Heater water too hot?
- J
  Joshua HendricksSep 4, 2025
  If the water from your A.O. Smith Water Heater is too hot, the temperature setting may be set too high. Adjust the temperature using the temperature controller or the remote controller.
C
Christine RobinsonSep 7, 2025
What to do if hot water turns cold and stays cold with A.O. Smith ATI-140H-N Water Heater?
- M
  Michelle GutierrezSep 7, 2025
  If the hot water from your A.O. Smith Water Heater turns cold and stays cold, check if the flow rate is sufficient to keep the water heater running. If a recirculation system is installed, ensure the recirculation line has enough check valves. Also, verify the gas supply valve is fully open and the filter on the cold water inlet is clean. Make sure your fixtures are free of debris and obstructions and check if the flow rate is too low.
W
williamjohnsonSep 12, 2025
How to get hot water faster from my A.O. Smith Water Heater?
- S
  Sheila BrownSep 12, 2025
  The time it takes to get hot water from your A.O. Smith Water Heater depends on the length of piping between the heater and the fixtures. The longer the distance or the bigger the pipes, the longer it will take. If you want hot water faster, consider a hot water recirculation system.

Summary

Installation Manual

SPECIFICATIONS

Detailed technical specifications and ratings for the water heater models.

INTRODUCTION

Overview of the manual's purpose and the water heater's features and operation.

SAFETY GUIDELINES

Crucial safety definitions, general precautions, and warnings for installation and operation.

INSTALLATION

General guidelines and procedures for installing the water heater.

CLEARANCES

Required minimum clearances around the water heater for safe installation.

INCLUDED ACCESSORIES

List of items included with the water heater for installation.

OPTIONAL ITEMS

List of optional accessories available for purchase and use with the water heater.

WARNING FOR INSTALLATIONS

Critical warnings and prohibited installation locations and configurations.

HIGH-ALTITUDE INSTALLATIONS

Instructions for adjusting DIPswitches based on installation altitude.

VENTING INSTRUCTIONS

Guidelines and requirements for properly venting the water heater exhaust.

-Exhaust vent (ABS, PVC, CPVC, or polypropylene vent)-

Specifics on using plastic vent materials, including maximum lengths and requirements.

-Exhaust vent (Stainless steel vent)-

Guidelines for using stainless steel vents, including maximum lengths and requirements.

-Common-venting system-

Procedures and considerations for common venting multiple water heaters.

-Vent termination clearances-

Required clearances for vent terminations to ensure safety and proper function.

-For sidewall terminations-

Specific clearance requirements for sidewall vent terminations.

-For rooftop terminations-

Clearance requirements for rooftop vent terminations.

GAS SUPPLY AND GAS PIPE SIZING

Information on gas supply types, pressure requirements, and pipe sizing.

-Measuring inlet gas pressure-

Procedure for measuring inlet gas pressure, to be performed by a professional.

-Natural Gas Supply Piping-

Charts and guidance for sizing natural gas supply piping.

-Propane (LP) Supply Piping-

Charts and guidance for sizing propane supply piping.

WATER CONNECTIONS

Instructions for connecting water supply lines, including shutoff valves and filters.

-Pressure relief valve-

Requirements and installation guidelines for the pressure relief valve.

CONDENSATE DRAIN

Information on handling and draining condensate water.

-Condensate Drain Connections-

Procedures for connecting condensate drains, with or without a neutralizer.

ELECTRICAL CONNECTIONS

Guidelines for making electrical connections, including grounding and power supply.

TEMPERATURE REMOTE CONTROLLER

Installation and wiring instructions for the temperature remote controller.

EASY-LINK SYSTEM

Instructions for connecting multiple water heaters in an Easy-Link system.

(C) Examples of incorrect settings and;or connections

Common mistakes in DIPswitch settings and wiring for the Easy-Link system.

MULTI-UNIT SYSTEM

Information on setting up a multi-unit system using a controller.

APPLICATIONS

Applications for space heating and dual-purpose heating systems.

-Space-Heating Applications-

Specific requirements for space heating applications, including air vents and flow rates.

-Recirculation-

Details on setting up and operating a recirculation system.

-Dual-purpose hot water heating- (Domestic and Space Heating):

Layout and considerations for combined domestic and space heating systems.

INITIAL OPERATION

Pre-operation checks and steps to start the water heater for the first time.

Owners Guide

OPERATING SAFETY

Essential safety instructions and warnings before operating the water heater.

FOR YOUR SAFETY READ BEFORE OPERATING

Critical safety warnings about fire, explosion, and gas leaks.

OPERATING INSTRUCTIONS

Step-by-step guide for safely starting and operating the water heater.

NORMAL OPERATION

How to operate the water heater using controllers and general operating guidelines.

TEMPERATURE CONTROLLER and REMOTE CONTROLLER

Explains the functions and displays of the temperature and remote controllers.

GENERAL

General operating tips and information, including flow rates and energy saving.

TEMPERATURE SETTINGS

How to adjust temperature settings using the controller or DIPswitches.

TEMPERATURE TABLE OF CONTROLLER

Tables showing output temperature based on various settings and inlet temperatures.

ADDITIONAL FEATURES

Information and unit conversion modes available on the controllers.

-Information mode-

Accessing information like inlet/outlet temps and water flow.

-Unit conversion mode-

Changing temperature and flow rate units between F/C and GPM/LPM.

TEMPERATURE SETTINGS ON THE PCB (WITHOUT REMOTE CONTROLLER)

Setting temperatures directly on the computer board via DIPswitches.

FLOW

Information on water flow rates and their limitations for different models.

FREEZE PROTECTION SYSTEM

Details on the unit's freeze protection mechanism and precautions.

MAINTENANCE AND SERVICE

Procedures for routine maintenance, cleaning, and servicing.

UNIT DRAINING and FILTER CLEANING

Steps for draining the unit and cleaning the cold water inlet filter.

TROUBLESHOOTING

Common problems and their solutions for water heater operation.

GENERAL

Troubleshooting common issues related to hot water temperature and amount.

ERROR CODES

Explanation of error codes displayed by the unit and their meanings.

-Fault Analysis of Error Codes-

Detailed analysis of error codes, their causes, and diagnostic steps.

COMPONENTS DIAGRAM

Visual diagrams of the water heater's internal components.

Case assembly

Exploded view of the water heater's outer casing and main assembly.

Computer board assembly

Diagram showing the computer board and associated components.

Burner assembly

Diagram illustrating the burner and related parts.

Water Way assembly

Diagram of the water flow paths and associated components.

PARTS LIST

A comprehensive list of all part numbers for the water heater models.

LIMITED WARRANTY

Details of the product warranty, coverage, and limitations.

A.O. Smith ATI-140H-N Specifications

General

Brand	A.O. Smith
Model	ATI-140H-N
Category	Water Heater
Type	Tankless
Fuel Type	Natural Gas
Maximum BTU Input	140, 000 BTU/hr
Energy Factor	0.82
Venting	Direct Vent
Ignition Type	Electronic
Gas Connection	3/4" NPT
Water Connection	3/4" NPT