UL 174
Standard for Household Electric Storage Tank Water Heaters

DETAILS
Edition Number:11ANSI Approved: 2016-12-15
Edition Date:2004-04-29DOD Approved:--
Price Code:DSCC Approved:--
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover household electric storage tank and small capacity storage tank water heaters rated no more than 600 volts and 12 kilowatts to be installed in accordance with the National Electrical Code, NFPA 70, and with model plumbing and mechanical codes.

    1.2 These requirements do not cover immersed electrode, side arm, booster, instantaneous or immersion type water heaters or water heating portions of water dispensing appliances. These requirements do not cover water heaters with a tank capacity of less than 1 gallon (3.8 L) or more than 120 gallons (454 L).

    1.3 Electric booster water heaters, electric commercial storage tank water heaters, and remote control assemblies for such heaters, rated 600 volts or less are not covered by this standard. They are covered in the Standard for Electric Booster and Commercial Storage Tank Water Heaters, UL 1453.

    1.4 Permanently installed electric water heaters, rated 600 volts or less, for heating the water supplied through plumbing to separately heated public or private pools or tubs, in which swimming, wading, bathing, or partial or total immersion of persons, is to be involved are not covered by this standard. They are covered in the Standard for Electric Water Heaters for Pools and Tubs, UL 1261.

    1.5 Water heaters rated 600 volts or less with a tank capacity of less than 1 gallon (3.8 liters) are not covered by this standard. They are covered under the Standard for Electric Heating Appliances, UL 499.

    1.6 A water heater intended for use in a hazardous location is to be judged on the basis of its compliance with these requirements; however, further examination and testing shall be conducted to determine whether it is acceptable for the intended use.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Components
          • 3 Units of Measurement
          • 4 Undated References
          • 5 Glossary
        • CONSTRUCTION
          • 6 Frame, Enclosures, and Outer Jacket
            • 6.1 General
            • 6.2 Enclosures
            • 6.3 Outer jacket
          • 7 Mechanical Assembly
          • 8 Accessibility of Live Parts
          • 9 Wetting of Live Parts
          • 10 Corrosion Resistance
            • 10.1 General
            • 10.2 Storage tanks
          • 11 Electrical Supply Connections – Permanent Connection
            • 11.1 General
            • 11.2 Field-wiring compartment
            • 11.3 Field-wiring terminals and leads
          • 12 Electrical Supply Connections – Cord Connection
            • 12.1 Power supply cords
            • 12.2 Bushings
            • 12.3 Strain relief
          • 13 Electrical Spacings
            • 13.1 General
            • 13.2 Reduction of spacings due to turning or shifting
          • 14 Grounding
            • 14.1 General
            • 14.2 Conductor identification
          • 15 Reduction of Risk of Injury
            • 15.1 Sharp edges
            • 15.2 Stability
            • 15.3 Surface temperatures
          • 16 Overcurrent Protection
          • 17 Materials in Contact with Water
            • 17.1 General
            • 17.2 Dip tubes
            • 17.3 Polymeric storage tank liner
          • 18 Current-Carrying Parts
          • 19 Internal Wiring
          • 20 Electrical Insulation
          • 21 Thermal Insulation
            • 21.1 General
            • 21.2 Polymeric foam
          • 22 Heating Elements
            • 22.1 General
            • 22.2 Sheathed elements
          • 23 Temperature-Regulating Controls
          • 24 Temperature-Limiting Controls
          • 25 Storage Tank
        • PERFORMANCE
          • 26 Power Input Test
          • 27 Insulation Resistance Test
          • 28 Temperature Test
            • 28.1 General
            • 28.2 Maximum load
            • 28.3 Surface temperatures
            • 28.4 Dry operation
          • 29 Water Temperature Test
          • 30 Dielectric Voltage-Withstand Test
          • 31 Mounting Test of Surface-Mounted Temperature Controls
            • 31.1 Horizontal pull
            • 31.2 Supply lead pull
          • 32 Barrier Pull Tests
          • 33 Water Capacity Test
          • 34 Grounding-Circuit Resistance Measurement Test
          • 35 Storage Tank Hydrostatic Pressure Test
          • 36 Nonmetallic Dip Tube Tests
            • 36.1 Deformation of weight loss
            • 36.2 Resistance to crushing
            • 36.3 Collapse
          • 37 Strain Relief Test
          • 38 Push Back Relief Test
          • 39 Electrical Disturbance Test of Foam Thermal Insulation
          • 40 Leakage Current Test
          • 41 Enclosure Strength Test
          • 42 Permanence of Markings
        • MANUFACTURING AND PRODUCTION TEST
          • 43 Production Line Dielectric Voltage-Withstand Test
        • RATINGS
          • 44 Electrical
          • 45 Tank Pressure and Capacity
        • MARKINGS
          • 46 Identification
          • 47 Ratings
          • 48 Warning Notices
          • 49 Informational Markings
        • INSTRUCTIONS
          • 50 General
          • 51 Safety Instructions
    • SAFETY OF SMART ENABLED HOUSEHOLD ELECTRIC STORAGE TANK WATER HEATERS
    • APPENDIX A