Chapter 5—Water heaters.
501.1 Applicability. The regulations of this chapter shall govern the construction, location, and installation of fuel burning and other types of water heaters heating potable water. The minimum capacity for water heaters shall be in accordance with the first hour rating listed in Table 501.1(2). See the Mechanical Code for combustion air and installation of all vents and their connectors. No water heater shall be hereinafter installed that does not comply with the manufacturer's installation instructions and the type and model of each size thereof approved by the authority having jurisdiction. A list of accepted water heater appliance standards is referenced in Table 501.1(1). Listed appliances shall be installed in accordance with the manufacturer's installation instructions. Unlisted water heaters shall be permitted in accordance with Section 504.3.2.
TABLE 501.1(2)1,3
Number of Bathrooms | 1 to 1.5 | 2 to 2.5 | 3 to 3.5 |
Number of Bedrooms | 1 | 2 | 3 | 2 | 3 | 4 | 5 | 3 | 4 | 5 | 6 |
First Hour Rating2, Gallons | 38 | 49 | 49 | 49 | 62 | 62 | 74 | 62 | 74 | 74 | 74 |
Notes: | 1The first hour rating is found on the "Energy Guide" label. |
| 2Nonstorage and solar water heaters shall be sized to meet the appropriate first hour rating as shown in the table, and shall be capable of delivering hot water at the maximum system demand flow, as calculated in Section 610.0 or Appendix A, as applicable. |
| 3For replacement water heaters, see Section 102.4. |
501.1.2 Consumer Electric Storage Water Heater Requirements. Consumer electric storage water heaters must have a modular demand response communications port compliant with the March 2018 version of the ANSI/CTA–2045-A communication interface standard, or equivalent and the March 2018 version of the ANSI/CTA-2045-A application layer requirements. The interface standard and application layer requirements required in this subsection are the versions established on March 16, 2018.
EXCEPTIONS: | 1. Water heaters manufactured prior to January 1, 2021. |
| 2. Electric storage water heaters other than heat pump type water heaters manufactured prior to January 1, 2022. |
501.1.3 Mini-tank Electric Water Heaters. The standby energy consumption of hot water dispensers and mini-tank electric water heaters manufactured on or after January 1, 2010, shall be not greater than 35 watts. Mini-tank electric water heaters shall be tested in accordance with the method specified in the California Code of 39 Regulations, Title 20, section 1604 in effect as of July 26, 2009.
504.1 Location. Water heater installation in bedrooms and bathrooms shall comply with one of the following:
(1) Fuel-burning water heaters may be installed in a closet located in the bedroom or bathroom provided the closet is equipped with a listed, gasketed door assembly and a listed self-closing device. The self-closing door assembly shall meet the requirements of Section 504.1.1. The door assembly shall be installed with a threshold and bottom door seal and shall meet the requirements of Section 504.1.2. All combustion air for such installations shall be obtained from the outdoors in accordance with the International Mechanical Code. The closet shall be for the exclusive use of the water heater.
(2) Water heater shall be of the direct vent type.
505.2 Safety Devices. All storage-type water heaters deriving heat from fuels or types of energy other than gas, shall be provided with, in addition to the primary temperature controls, an over-temperature safety protection device constructed, listed, and installed in accordance with nationally recognized applicable standards for such devices and a combination temperature and pressure relief valve.
506.0 Combustion Air. For issues relating to combustion air, see the Mechanical Code.
Sections 506.1 through 506.9 are not adopted.
Sections 507.6 through 507.9 are not adopted.
507.2 Seismic Provisions. Water heaters shall be anchored or strapped to resist horizontal displacement due to earthquake motion. Strappings shall be at points within the upper one-third and lower one-third of its vertical dimensions. At the lower point, a distance of not less than four (4) inches (102 mm) shall be maintained from the controls to the strapping.
507.13 Installation in Garages. Appliances in garages and in adjacent spaces that open to the garage and are not part of the living space of a dwelling unit shall be installed so that burners, burner-ignition devices and ignition sources are located not less than eighteen (18) inches above the floor unless listed as flammable vapor ignition resistant.
507.16 Venting of Flue Gases - Delete entire section.
Sections 507.18 through 507.22 are not adopted.
509.0 Venting of Equipment. Delete entire section.
510.0 Sizing of Category I Venting Systems. Delete entire section.
[Statutory Authority: RCW
19.27.031 and
19.27.074. WSR 23-23-108, § 51-56-0500, filed 11/15/23, effective 3/15/24; WSR 23-02-057, 23-12-110, and 23-20-029, § 51-56-0500, filed 1/3/23, 6/7/23, and 9/25/23, effective 3/15/24. Statutory Authority: RCW
19.27.035 and
19.27.074. WSR 21-01-125, § 51-56-0500, filed 12/15/20, effective 1/15/21. Statutory Authority: RCW
19.27.031 and
19.27.074. WSR 20-02-072, § 51-56-0500, filed 12/26/19, effective 7/1/20; WSR 17-10-074, § 51-56-0500, filed 5/3/17, effective 6/3/17; WSR 16-02-044, § 51-56-0500, filed 12/30/15, effective 7/1/16. Statutory Authority: RCW
19.27.074,
19.27.031 and chapters
19.27 and
34.05 RCW. WSR 13-04-054, § 51-56-0500, filed 2/1/13, effective 7/1/13; WSR 11-05-037, § 51-56-0500, filed 2/8/11, effective 7/1/13; WSR 10-03-101, § 51-56-0500, filed 1/20/10, effective 7/1/10. Statutory Authority: RCW
19.27.190,
19.27.020 and chapters
19.27 and
34.05 RCW. WSR 07-01-094, § 51-56-0500, filed 12/19/06, effective 7/1/07. Statutory Authority: RCW
19.27.031 and
19.27.074. WSR 04-01-110, § 51-56-0500, filed 12/17/03, effective 7/1/04; WSR 02-01-114, § 51-56-0500, filed 12/18/01, effective 7/1/02.]
