CSA/ANSI Z21.10.1:19 • CSA 4.1:19

National Standard of Canada American National Standard

Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less

REVISED SEPTEMBER 2020

Revision History

CSA/ANSI Z21.10.1:19 • CSA 4.1:19, Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less

Administrative update — September 2020

Revision History page: “Revision from previous edition” updated

Standards Update Service

CSA/ANSI Z21.10.1:19 • CSA 4.1:19

November 2019

Title: Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less

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National Standard of Canada American National Standard

CSA/ANSI Z21.10.1:19 • CSA 4.1:19

Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less

Interprovincial Gas Advisory Council

®A trademark of the Canadian Standards Association and CSA America Standards Inc., operating as “CSA Group”

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Approved on September 23, 2019 by ANSI Approved on October 9, 2019 by IGAC Effective in Canada May 1, 2021

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ICS 97.100.20; 91.140.65

ISBN 978-1-4883-1533-6

© 2019 Canadian Standards Association

All rights reserved. No part of this publication may be reproduced in any form whatsoever without the prior permission of the publisher.

Contents

Interprovincial Gas Advisory Council 4

Canadian Technical Committee on Gas Appliances and Related Accessories 6

Z21/83 Technical Committee on Performance and Installation of Gas Burning Appliances and Related Accessories 9

Joint Technical Subcommittee on Gas-Fired Water Heaters 12

Preface 18

1. Scope 21

   
   

2. Reference publications 22

   
   

3. Definitions 27

   
   

4. Construction 38

   1. General construction and assembly 38

   2. Materials 44

   3. Combustion air supply 48

   4. Heat pipe heat exchangers 48

   5. Water heater openings 49

   6. Burners 49

   7. Flame spreaders 51

   8. Primary air adjustment means 51

   9. Main burner orifices and orifice fittings 52

   10. Automatic gas ignition systems 53

   11. Pilot gas filters 56

   12. Gas and water connections 56

   13. Opening for relief valves 58

   14. Dip tubes 59

   15. Manually operated gas valves 59

   16. Gas appliance pressure regulators 60

   17. Adjustment of minimum input rating 61

   18. Thermostats 61

   19. Automatic valves 61

   20. Bleeds and vents 62

   21. Automatic gas shutoff systems 62

   22. Relief valves 63

   23. Automatic flammable vapor sensor systems and components 64

   24. Condensate disposal 64

   25. Flue collars 64

   26. Flue pipe extensions 64

   27. Draft hoods 65

   28. Non-metallic vent and air intake connection strength test 66

   29. Automatic vent damper devices 66

   30. Automatic flue damper devices 67

   31. Electrical equipment and wiring 69

   32. Vent and air-intake pipes of direct vent systems 83

   33. Instructions 84

   34. Marking 97

       
       

5. Performance 110

   1. General 110

   2. Test gases 115

   3. Test pressures and burner adjustments 117

   4. Combustion 117

   5. Burner and pilot operating characteristics 120

   6. Category determination 122

   7. Piloted ignition systems 126

   8. Proved igniter systems 131

   9. Direct ignition systems 133

   10. Heat roll out safety shutoff means 135

   11. Heat required to supply daily quota of hot water 136

   12. Gas appliance pressure regulators 138

   13. Storage heater temperature limits 138

   14. Temperature limiting systems 140

   15. Evaluation of burn hazard potential of exterior surfaces 141

   16. Wall, floor, and ceiling temperatures 145

   17. Non-metallic vent material temperatures 147

   18. Flue gas temperature 148

   19. Temperature of manually operated parts 149

   20. Burner and flame spreader temperatures 149

   21. Flue collars 151

   22. Draft hoods 151

   23. Automatic vent damper devices 155

   24. Automatic flue damper devices 155

   25. Draft tests for water heaters equipped with power burners 159

   26. Wind test 161

   27. Safety circuit analysis 164

   28. Capacities of storage vessels 164

   29. Hydrostatic test 165

   30. Heat pipe heat exchanger pressure 166

   31. Burner durability 167

   32. Venting systems for Category II, III, or IV water heaters 167

   33. Condensate disposal system(s) 168

   34. Rain tests 169

   35. Direct vent systems 171

   36. Marking material adhesion and legibility 178

   37. Flammable vapors ignition resistance 179

   38. Resistance to lint, dust and oil accumulation 188

   39. Corrugated metal tubing 192

   40. Condensate disposal system(s) 195

       
       

6. Manufacturing and production tests 195

7. Items unique to the United States 197

   1. High altitude 197

   2. Marking material adhesion and legibility 197

   3. General construction 197

      
      

8. Items unique to Canada 197

   1. High altitude 197

   2. Storage vessels 197

   3. Outdoor installation 198

      1. Components for low temperature operation 198

      2. Rating plate marking for outdoor heaters 198

   4. Draft hoods 198

   5. Pilot burners and safety shut-off devices 198

   6. French translations for quoted instructions and markings 198

Annex A (normative) — Outline of lighting instructions for appliances equipped with continuous pilots 217

Annex B (normative) — Outline of operating instructions for appliances equipped with intermittent pilot or interrupted pilot systems 220

Annex C (normative) — Outline of operating instructions for appliances equipped with direct ignition systems 223

Annex D (normative) — Flammable vapors label 226

Annex E (normative) — Scald hazard label 228

Annex F (normative) — Optional provisions for listed gas appliance conversion kits 229

Annex G (informative) — Pertinent references to ANSI Y14.15 232

Annex H (informative) — Wire color designations 233

Annex I (informative) — Recommended wire color usage 234

Annex J (informative) — Preferred graphic symbols of commonly used items, extracted from standard ANSI/IEEE 315, Graphic symbols for electrical and electronics diagrams, and abbreviations for these items 235

Annex K (informative) — Sample failure modes and effects analysis for component miswiring* 237

Annex L (informative) — Table of conversion factors 238

Annex M (informative) — Lint, dust, and oil test equipment and procedures (see Clause 5.38) 241

Preface

This is the eighth edition of CSA/ANSI Z21.10.1 • CSA 4.1, Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less. It supersedes the previous editions published in 2017, 2014, 2013, 2009, 2004, 2001 and 1998.

This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard.

This Standard was prepared by the Joint Technical Subcommittee on Gas-Fired Water Heaters under the jurisdiction of the Z21/83 Technical Committee on Performance and Installation of Gas Burning Appliances and Related Accessories and the Strategic Steering Committee on Fuels and Appliances. It has been formally approved by the Z21/83 Technical Committee, the Canadian Technical Committee on Gas Appliances and Related Accessories, and the Interprovincial Gas Advisory Council.

This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.

This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard.

Interpretations: The Strategic Steering Committee on Fuels and Appliances has provided the following direction for the interpretation of standards under its jurisdiction: “The literal text shall be used in judging compliance of products with the safety requirements of this Standard. When the literal text cannot be applied to the product, such as for new materials or construction, and when a relevant CSA committee interpretation has not already been published, CSA Group’s procedures for interpretation shall be followed to determine the intended safety principle.”

Notes:

1. Use of the singular does not exclude the plural (and vice versa) when the sense allows.

2. Although the intended primary application of this Standard is stated in its Scope, it is important to note that it remains the responsibility of the users of the Standard to judge its suitability for their particular purpose.

3. This Standard was developed by consensus, which is defined by CSA Policy governing standardization — Code of good practice for standardization as “substantial agreement. Consensus implies much more than a simple majority, but not necessarily unanimity”. It is consistent with this definition that a member may be included in the Technical Committee list and yet not be in full agreement with all clauses of this Standard.

4. To submit a request for interpretation of this Standard, please send the following information to inquiries@csagroup.org and include “Request for interpretation” in the subject line:

   1. define the problem, making reference to the specific clause, and, where appropriate, include an illustrative sketch;

   2. provide an explanation of circumstances surrounding the actual field condition; and

   3. where possible, phrase the request in such a way that a specific “yes” or “no” answer will address the issue.

      Committee interpretations are processed in accordance with the CSA Directives and guidelines governing standardization and are available on the Current Standards Activities page at standardsactivities.csa.ca.

5. This Standard is subject to review within five years from the date of publication. Suggestions for its improvement will be referred to the appropriate committee. To submit a proposal for change, please send the following information to inquiries@csagroup.org and include “Proposal for change” in the subject line:

   1. Standard designation (number);

   2. relevant clause, table, and/or figure number;

   3. wording of the proposed change; and

   4. rationale for the change.

History of the development of standards for Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less

Note: This history is informative and is not part of the standard.

With the onset of the Free Trade Agreement between the United States and Canada on January 2, 1988, significant attention was given to the harmonization of the United States and Canadian safety standards addressing gas-fired equipment for residential, commercial, and industrial applications. It was believed that the elimination of the differences between the standards would remove potential trade barriers and provide an atmosphere in which North American manufacturers could market more freely in the United States and Canada. The harmonization of these standards was also seen as a step toward harmonization with international standards. Joint subcommittees were established to facilitate the standards harmonization process between the United States and Canada.

The draft harmonized standard was based on current coverage from the American National Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Rating of 75,000 Btu Per Hour or Less, ANSI Z21.10.1-1993 and Addenda Z21.10.1a-1994, Z21.10.1b-1994, Z21.10.1c-1996 and the

Canadian Standard for Gas-Fired Automatic Storage Type Water Heaters with Inputs Less than

75,000 Btuh, CAN1-4.1-M85. The draft was subsequently issued for public review and comment during March 1996.

Following reconsideration and modification of the proposed draft standard, in light of comments received, the joint water heater subcommittee, at its July 24-25, 1996 meeting, recommended the proposed draft to the Z21 Committee and the CGA Standards Steering Committee for approval.

The proposed draft of the harmonized standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, as modified by the joint subcommittee at its meeting of July 24-25, 1996, was approved by the Z21/83 Committee at its April 17, 1997 meeting and by the CGA Standards Steering Committee on May 6, 1997.

The first edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council in September 10, 1997 and by the American National Standards Institute Inc. on March 3, 1998.

The second edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council in August 1, 2001 and by the American National Standards Institute Inc. on December 20, 2001.

The third edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council in May 18, 2004 and by the American National Standards Institute Inc. on July 2, 2004.

The fourth edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council on January 15, 2009 and by the American National Standards Institute Inc. on June 20, 2008.

The fifth edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial

Gas Advisory Council on February 25, 2013 and by the American National Standards Institute Inc. on January 10, 2013.

The sixth edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council on November 26, 2014 and by the American National Standards Institute Inc. on August 15, 2014.

The seventh edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council on August 17, 2017, and by the American National Standards Institute Inc. on August 21, 2017.

This, the eighth edition of the harmonized Z21/CSA Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, was approved by the Canadian Interprovincial Gas Advisory Council on October 9, 2019, and by the American National Standards Institute Inc. on September 23, 2019.

The previous editions of the Standard for Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 Btu per Hour or Less, and addenda thereto, approved by the Interprovincial Gas Advisory Council and American National Standards Institute, Inc. are as follows:

Z21.10.1-1998 • CSA 4.1-M98 Z21.10.1a-2000 • CSA 4.1a-2000 Z21.10.1b-2000 • CSA 4.1b-2000

Z21.10.1-2001 • CSA 4.1-2001 Z21.10.1a-2002 • CSA 4.1a-2002 Z21.10.1b-2004 • CSA 4.1b-2004

Z21.10.1-2004 • CSA 4.1-2004 Z21.10.1a-2006 • CSA 4.1a-2006 Z21.10.1b-2006 • CSA 4.1b-2006

Z21.10.1-2009 • CSA 4.1-2009 Z21.10.1a-2009 • CSA 4.1a-2009 Z21.10.1b-2011 • CSA 4.1b-2011

Z21.10.1-2013 • CSA 4.1-2013

Z21.10.1-2014 • CSA 4.1-2014

Z21.10.1-2017 • CSA 4.1-2017

The following identifies the designation and year of the eighth edition of the Standard:

CSA/ANSI Z21.10.1:19 • CSA 4.1:19

Note: This edition of CSA/ANSI Z21.10.1 • CSA 4.1 incorporates changes to the 2017 edition. Changes, other than editorial, are denoted by a delta in the margin.

CSA/ANSI Z21.10.1:19 • CSA 4.1:19

Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less

1 Scope

1.1

This Standard applies to newly produced, automatic storage water heaters having input ratings of 75,000 Btu/hr (21 980 W) or less (see Clause 3, Definitions), hereinafter referred to as water heaters or appliances, constructed entirely of new, unused parts and materials:

1. for use with natural gas;

2. for use with manufactured gas;

3. for use with mixed gas;

4. for use with liquefied petroleum gases;

5. for use with LP gas-air mixtures;

6. for recreational vehicle installation for use with liquefied petroleum gases only (see Clause 4.1.26);

7. for manufactured home (mobile home) installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.25);

8. for recreational vehicle installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see

   Clause 4.1.26); and

9. for use with combination potable water/space heating applications (see Clause 4.1.29 and Clause 3, Definitions).

1.2

This Standard also applies to water heaters incorporating heat pipe heat exchangers (see Clause 4.4, Heat pipe heat exchangers).

1.3

Direct vent water heaters anticipated by this Standard are essentially balanced flue appliances with the air intake and vent outlet in close proximity. Other designs are to be subjected to such additional tests as believed necessary at the discretion of the testing agency.

1.4

Water heaters for installation in recreational vehicles are to be of the direct vent type.

1.5

This Standard also applies to water heaters with draft hoods which are factory-equipped with automatic vent damper devices (see Clause 3, Definitions), hereinafter referred to as vent damper devices.