The short answer
- From January 1, 2028, a gas tank water heater made after that date can't be sold or installed in the Bay Area.
- A working gas water heater can stay. Nothing has to come out.
- Gas tank heaters made before 2028 can still be sold and installed, while stores have them.
- Stoves, dryers, fireplaces, and propane aren't covered.
What is zero-NOx?
NOx is nitrogen oxides, the gases a gas flame makes. They feed smog. The Air District links gas water heaters and furnaces to as many as 85 early deaths and 15,000 asthma attacks a year in the Bay Area.
A zero-NOx water heater gives off none while it runs. No gas model does today, so the choice is electric: a heat pump water heater or a plain electric tank.
Does it apply to me?
It covers Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, and Santa Clara counties, plus southwestern Solano and southern Sonoma.
| Your water heater | What applies |
|---|---|
| Still works | Nothing. Keep it. |
| Gas tank over 30 gallons, made after Jan 1, 2028 | Can't be sold or installed |
| Gas tankless | Covered from units made after Jan 1, 2033 |
| 30 gallons or smaller, or a mobile home | Not covered |
| Building with 5 or more homes, or deed-restricted affordable housing | Gas allowed with a certificate, until 2033 |
You may be exempt if:
- You're in a low-income program, or earn 80% or less of the area median, or your mortgage and property taxes take 28% or more of your income.
- A licensed contractor certifies your panel is under 100 amps or full, or a new circuit would need more than 50 feet of conduit.
- There's no room for a heat pump: a small closet that can't be vented, or a garage ceiling under 7.2 feet.
Every exemption needs a certificate from the Air District before the install. The room and panel exemptions work once per address. A contractor can also put in a temporary gas heater in an emergency, for up to 12 months. The Air District's Building Appliances page has the details.
When should I buy?
Before yours fails. Most water heaters get replaced the day they stop working. That's when you have the fewest choices.
- Check its age. It's on the label, or coded in the serial number.
- Get a heat pump quote now, while you have time to compare.
- Ask about a 120-volt model. It can often avoid a panel upgrade.
- Line up rebates before you buy. Some pay only if you're approved first.
The worst day to choose a water heater is the day yours stops working.
What does it cost to install, after rebates?
Before rebates, the Air District puts a heat pump install at about $7,000 on average. A gas one is about $3,600.
Rebates now depend on your address:
- Federal tax credit: ended with 2025.
- State programs (TECH Clean California, HEEHRA): fully reserved for single-family homes as of October 2026.
- Local programs are what's left: your utility, your community energy supplier, or your city. Some pay thousands.
Our calculator starts at $5,200 for a straightforward swap ($2,200 unit, $500 parts, $2,500 labor), then takes off the rebates for your ZIP code. A panel upgrade or moving the heater adds to that. What's still open, program by program.
What does it cost to run?
The Air District says a heat pump water heater is typically cheaper to run than gas. How much cheaper depends on your electric plan, your gas price, how many people live with you, and your weather.
The calculator asks for all four, then prices your rate plan hour by hour against a real heat pump water heater metered every 15 minutes for a year.
Run the water heater calculator →
On PG&E, a heat pump can qualify you for the Electric Home rate. Will a heat pump lower my bill?
Already have solar? Pair it with a heat pump water heater, then run it as a thermal battery.
Sources
- Bay Area Air District: Board adopts water heater rule amendments, delays to January 2028 (November 4, 2026)
- Bay Area Air District: Rule 9-6, amended text (Sections 9-6-111 to 114, 301.5, 303.5, and 405)
- Bay Area Air District: Rules 9-4 and 9-6, Building Appliances
- Bay Area Air District: Appliance Rules FAQ
- Canary Media: Bay Area looks to exempt some households (install cost, May 20, 2026)
- SPUR: Clean water heating in the Bay Area, state of play for 2026 (gas install cost)
What would a heat pump cost you?
Our free calculator uses your ZIP code, your electric plan, and a heat pump water heater metered for a year. About 2 minutes, no sign-up.
- What your water heater costs to run now, and what a heat pump would cost.
- The rebates for your ZIP code, taken off the install.
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Common questions
When does the Bay Area gas water heater ban start?
January 1, 2028. On November 4, 2026, the Bay Area Air District's board moved it from January 1, 2027. It covers gas tank water heaters over 30 gallons that are made after that date.
Do I have to replace my gas water heater?
No. The rule only limits what can be sold and installed. A working gas water heater can stay as long as it lasts.
What is a zero-NOx water heater?
One that gives off no nitrogen oxides while it runs. No gas water heater does today, so in practice it means electric: a heat pump water heater or an electric tank.
Can I still buy a gas water heater after 2028?
A gas tank heater made before January 1, 2028 can still be sold and installed, while stores have them. Gas tankless heaters are covered only from units made after January 1, 2033. Otherwise you need an exemption certificate from the Air District, or a heater of 30 gallons or less, or a mobile home.
Does the rule ban gas stoves?
No. It doesn't cover stoves, dryers, or fireplaces, and it doesn't cover propane. Gas furnaces fall under a separate rule, from 2029.
Who is exempt from the Bay Area water heater rule?
Owners in a low-income program or earning 80% or less of the area median income, or paying 28% or more of income on mortgage and property taxes. Also, once per address, homes with no room or ventilation for a heat pump, and homes where a licensed contractor certifies the panel is under 100 amps, is full, or needs a run over 50 feet. Every exemption needs a certificate from the Air District before the install.
How much does a heat pump water heater cost to install in the Bay Area?
About $7,000 on average before rebates, by the Air District's analysis, roughly double a gas water heater. Rebates now come mostly from local programs, so the price after rebates depends on your ZIP code. Our free calculator works it out.
Does the rule apply to renters?
The owner replaces the water heater, so the rule falls on the landlord, not the renter.
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