10.3 Mandatory Requirements §150.0(n) and §150.0(t-v)
Electric readiness requires the following for the applicable gas appliances listed in Table 10-1.
Table 10-1 summarizes the electrical capacity, panel, and other requirements for electric-readiness for each gas appliance installed in a new single family building. There are no electric ready requirements for additions or alterations. There are no performance or prescriptive electric ready requirements for single family buildings.
These requirements are for newly constructed buildings and are not applicable to additions or alterations. Moreover, these requirements are not applicable when electric equipment is installed.
Table 10-1: Summary of Compliance Requirements
Gas or Propane Equipment Installed | Electrical Capacity requirements for new circuit (amps, volts) | Panel requirements | Other Requirements |
Water heater §150.0(n) | 1. 125V, 20 amp receptacle with copper 120V/240V, 10 AWG, 3-conductor wire. Unused conductor shall be labeled and electrically isolated. OR 2. 240V, 30 amp dedicated circuit | 1. Reserved space (labeled “For Future 240V use”) for single pole circuit breaker adjacent to 125V, 20A circuit breaker. OR 2. Reserved space (labeled “For Future 240V use”) for double pole circuit breaker | A designated space for a future HPWH (2.5 ft x 2.5 ft wide x 7 ft high) Condensate drain no more than 2 inches higher than the base of installed water heater to allow for natural drainage without pump assistance |
Furnace §150.0(t) | 240V, 30 amp | Reserved space for double pole circuit breaker | n/a |
Range §150.0(u) | 240V, 50 amp | Reserved space for double pole circuit breaker | n/a |
Clothes dryer §150.0(v) | 240V, 30 amp | Reserved space for double pole circuit breaker | n/a |
10.3.1 Water Heater
The following mandatory requirements apply to gas or propane water heaters serving single family buildings. These requirements make it easier for someone to retrofit existing water heater with a HPWH in the future. Wiring for a future HPWH during initial construction stage is much less costly than trying to retrofit it later.
10.3.1.1 Designated Space
A designated space needs to be reserved for installation of a future HPWH. That space needs to be 2.5 feet wide by 2.5 feet deep by 7 feet tall. This space can be located where the gas or propane water heater is installed. If there is not adequate space at the installed water heater location, then another suitable location should be identified.
10.3.1.2 Electrical Requirements
The goal of this requirement is to allow easy installation of a HPWH, which typically require a 240V circuit, when the existing gas water heater is replaced.
If the designated HPWH space is within 3 feet of the gas water heater, a dedicated 125-volt (V), 20 amp electrical receptacle shall be installed that is within 3 feet of the water heater and accessible to the water heater with no obstructions. The wiring to this dedicated receptacle shall be connected to a 120/240V, three conductor, minimum 10 AWG branch circuit. The ends of the unused conductor must be labeled as “spare” and be electrically isolated.
Additionally, a reserved single pole circuit breaker space must be placed in the electrical panel next to the circuit breaker for the branch circuit and labeled with the words “Future 240V Use.”
If the designated HPWH space is more than 3 feet from the gas water heater, a 240V branch circuit must be installed rated at a minimum of 30 amps with no obstructions, in addition to a dedicated space in the main service panel for a future double pole breaker that will serve the future HPWH. The dedicated space in the panels shall be identified as “Future 240V Use”. The circuit shall be dedicated to future electric replacement equipment and cannot be used for other appliances.
10.3.1.3 Condensate Drain
A condensate drain must be placed near the water heater no higher than 2 inches above the base of the tank. This will allow for gravity flow of the condensate without relying on a sump pump.
10.3.1.4 Hot and Cold Water Supply
If the designated HPWH space is more than 3 feet from the gas water heater, both cold water and hot water supply piping, exposed and readily accessible to serve a future HPWH, must be provided at the designated HPWH location. The location shall have a dedicated cold water supply, or a cold water supply shall pass through the designated location before reaching the gas water heater. Hot water supply from the gas water heater must be routed to the designated HPWH location first before serving any of the hot water fixtures in the house.
10.3.2 Space Heater
When gas furnaces are installed, the following electric-ready requirements must be met.
- Installation of branch circuits within 3 feet of the gas furnace with no obstructions. The circuit shall be 240V rated at a minimum of 30 amps. The circuit shall be dedicated to future electric replacement equipment and cannot be used for other appliances. A receptacle is not required, but the unused circuits must have a blank cover identified as “240V ready”. Other electrical components must be installed in accordance with the California Electrical Code.
- Dedicated space in the main service panel for a double pole breaker that will serve the future space heating. The dedicated space in the panels shall be identified as “Future 240V Use.” The code does not require the installation of breakers at time of construction.
If gas equipment other than a furnace is installed these electric ready requirements do not apply.
10.3.3 Cooktops
When gas cooktops are installed, the following electric-ready requirements must be met. Note that this requirement applies when installing a gas range but is not required for gas ovens when installed as a separate appliance.
- Installation of branch circuits within 3 feet of the gas cooktop with no obstructions. The circuit shall be 240V rated at a minimum of 50 amps. The circuit shall be dedicated to future electric replacement equipment and cannot be used for other appliances. A receptacle is not required, but the unused circuits must have a blank cover identified as “240V ready”. Other electrical components must be installed in accordance with the California Electrical Code.
- Dedicated space in the main service panel for a double pole breaker that will serve the future electric cooktop. The dedicated space in the panels shall be identified as “Future 240V Use.” The code does not require the installation of breakers at time of construction.
These electric ready requirements do not apply to stand-alone ovens.
10.3.4 Clothes Dryer
When gas piping to serve a clothes dryer is installed, the following electric-ready requirements must be met.
- Installation of a branch circuit within 3 feet of and accessible to the dryer location with no obstructions. The circuit shall be 240V rated at a minimum of 30 amps. The circuit shall be dedicated to future electric replacement equipment and cannot be used for other appliances. A receptacle is not required, but the unused circuits must have a blank cover identified as “240V ready”. Other electrical components must be installed in accordance with the California Electrical Code.
- Dedicated space in the main service panel for a double pole breaker that will serve the future electric clothes dryer. The dedicated space in the panels shall be identified as “Future 240V Use.” The code does not require the installation of breakers at time of construction.
10.3.5 Gas Uses not Covered by Electric Ready Requirements
Any gas appliances not listed in Table 10-2 are not required to meet the mandatory electric ready requirements. This includes outdoor grills, barbeque pits, fireplaces, and stand-alone ovens.